definitions f5

• Reiter's syndrome is one of the seronegative spondyloarthropathies, so called because serum rheumatoid factor is not present in these forms of inflammatory arthritis. There is an international consensus that the term reactive arthritis should replace the name "Reiter's syndrome" to describe this constellation of signs and symptoms. Unfortunately, the original name is still associated with the syndrome. Reiter's syndrome is an asymmetric polyarthritis that affects mainly the lower extremities and is associated with one or more of the following:
• � Urethritis
• � Cervicitis
• � Dysentery
• � Inflammatory eye disease
• � Mucocutaneous lesions

Renal artery stenosis (RAS) is the progressive narrowing of the renal artery and may be acute or chronic. RAS may cause renovascular hypertension or ischemic nephropathy.

Renal cell adenocarcinoma (RCA) is a primary adenocarcinoma originating in the renal parenchyma from the malignant transformation of proximal renal tubular epithelial cells.

Acute renal failure (ARF) is the rapid impairment in renal function resulting in retention of products in the blood that are normally excreted by the kidneys.


Chronic renal failure (CRF) is a progressive decrease in renal function (glomerular filtration rate [GFR] <60 ml/min for >3 mo) with subsequent accumulation of waste products in the blood, electrolyte abnormalities, and anemia. The National Kidney Foundation Disease Outcomes Quality Initiative defines chronic kidney disease (CKD) as follows, regardless of clinical diagnosis: kidney damage (usually defined as an albumin-creatinine ratio [ACR] >=30 mg/g) or a glomerular filtration rate (GFR) <60 ml/min per 1.73 m2 (usually estimated from the serum creatinine level) for at least 3 mo.

• Renal tubular acidosis (RTA) is a disorder characterized by inability to excrete H1 or inadequate generation of new HCO3 There are four main types of renal tubular acidosis described in the medical literature:
• � Type I (classic, distal RTA): abnormality in distal hydrogen secretion, resulting in hypokalemic hyperchloremic metabolic acidosis.
• � Type II (proximal RTA): decreased proximal bicarbonate reabsorption, resulting in hypokalemic hyperchloremic metabolic acidosis.
• � Type III (RTA of glomerular insufficiency): normokalemic hyperchloremic metabolic acidosis as a result of impaired ability to generate sufficient NH3 in the setting of decreased glomerular filtration rate (<30 ml/min). This type of RTA is described in older textbooks and is considered by many not to be a distinct entity.
• � Type IV (hyporeninemic hypoaldosteronemic RTA): aldosterone deficiency or antagonism, resulting in decreased distal acidification and decreased distal sodium reabsorption with subsequent hyperkalemic hyperchloremic acidosis.

Renal vein thrombosis is the thrombotic occlusion of one or both renal veins.

Respiratory syncytial virus (RSV) is an RNA virus that tends to form syncytia in tissue culture. RSV causes repeated acute respiratory tract infections in people of all ages. It is highly contagious and is the leading cause of severe lower respiratory tract infections in infants and young children, while it usually manifests as URIs, bronchiolitis, or tracheobronchitis in older children and adults.

Restless legs syndrome (RLS) is an awake phenomenon consisting of an urge to move legs, usually associated with feeling of discomfort in legs.

Retinal detachment is a retinal separation in which the inner or neural layer of the retina separates from the pigment epithelial layer. It results from numerous causes.

In a retinal hemorrhage, blood accumulates in the retinal and subretinal areas as a result of multiple causes.

Retinitis pigmentosa is a generalized retinal pigment degeneration associated with a variety of inheritance patterns resulting in decreased vision. A simple recessive pattern is most severe. It may be associated with some rare neurologic syndromes.


Retinoblastoma is an inherited, highly malignant congenital neoplasm arising from the neural layers of the retina.

Diabetic retinopathy is an eye abnormality of the retina associated with diabetes and consisting of microaneurysms, punctate hemorrhages, white and yellow exudates, flame hemorrhages, and neovascular vessel growth and can ultimately end in blindness. Diabetic retinopathy can be classified into two stages: nonproliferative and proliferative

Retropharyngeal abscess is a soft tissue infection of the throat involving retropharyngeal space. The anatomic boundaries of the retropharyngeal are the middle layer of the deep cervical fascia (abutting the posterior esophageal wall) anteriorly and the deep layer of the deep cervical fascia posteriorly. These two fasciae fuse inferiorly at the level between the first and second thoracic vertebra.

Reye's syndrome is a postinfectious triad consisting of encephalopathy, fatty liver degeneration, and transaminase elevation.

Rh incompatibility occurs when an absence of the D antigen on maternal red blood cells (RBCs) and its presence on fetal RBCs causes risk of isoimmunization.

Rhabdomyolysis is the dissolution or disintegration of muscle, which causes membrane lysis and leakage of muscle constituents, resulting in the excretion of myoglobin in the urine. Renal damage can occur as a result of tubular obstruction by myoglobin as well as hypovolemia.

Rheumatic fever is a multisystem inflammatory disease that occurs in the genetically susceptible host after a pharyngeal infection with group A streptococci..


Rheumatoid arthritis (RA) is a systemic disorder characterized by chronic joint inflammation that most commonly affects peripheral joints. This process results in the development of pannus, a destructive tissue that damages cartilage.

Allergic rhinitis is an IgE-mediated hypersensitivity response to nasally inhaled allergens that causes sneezing, rhinorrhea, nasal pruritus, and congestion. It may be seasonal or perennial.

Rickets is a systemic disease of infancy and childhood in which mineralization of growing bone is deficient as a result of abnormal calcium, phosphorus, or vitamin D metabolism. Osteomalacia is the same condition in the adult. Renal osteodystrophy is a term used to describe a similar condition in patients with chronic kidney disease. Certain forms of the disorder may respond only to high doses of vitamin D and are referred to as vitamin D resistant rickets (VDRR).

Rocky Mountain spotted fever (RMSF) is a lifethreatening, tick-borne febrile illness caused by infection with Rickettsia rickettsii. The infection occurs when R. rickettsii in the salivary glands of a vector tick is transmitted into the dermis, spreading and replicating in the cytoplasm of endothelial cells and eliciting widespread vasculitis and end-organ damage.

Rosacea is a chronic skin disorder characterized by papules and pustules affecting the face and often associated with flushing and erythema.

Roseola is a benign viral illness found in infants and characterized by high fevers, followed by a rash.

The rotator cuff comprises four muscle tendon units that stabilize the humeral head within the shoulder joint and aid in moving the upper extremity. Rotator cuff syndrome refers to a spectrum of afflictions involving the tendons of the rotator cuff (primarily the supraspinatus), ranging from simple strains and tendinitis to complete, massive rupture with cuff-tear arthropathy.

Rubella is a mild illness caused by the rubella virus that can cause severe congenital problems by in vitro transmission to a fetus when a pregnant woman becomes infected.

Salivary gland neoplasms are benign or malignant tumors of a salivary gland (parotid, submandibular, or sublingual).

Salmonellosis is an infection caused by one of several serotypes of Salmonella.

Sarcoidosis is a chronic multisystem granulomatous disease characterized histologically by the presence of nonspecific, noncaseating granulomas.

Scabies is a contagious disease caused by the mite Sarcoptes scabiei.

Scarlet fever is a rash involving the skin and tongue and complicating streptococcal group A pharyngitis.

Schistosomiasis is caused by infection with parasite blood flukes known as schistosomes.


Schizophrenia is a disorder that causes significant distortions in thinking, perception, speech, and behavior. Characteristics include psychosis, apathy, social withdrawal, and cognitive impairment, which result in significant social impairment.

Scleritis is inflammation of the sclera.

• Scleroderma (systemic sclerosis [SSc]) is a connective tissue disorder that is characterized by thickening and fibrosis of the skin and variably severe involvement of diverse internal organs. It can be subdivided into two major subgroups:
• (1) limited cutaneous SSc (lcSSc), which involves mainly the face, neck, arms, and hands; and
• (2) diffuse cutaneous SSc (dcSSc), which affects the skin in a more generalized distribution including the entire extremities, face, neck, and trunk. Both subgroups typically have characteristic internal organ involvement.

Scoliosis is a lateral curvature of the spine in the upright position, usually 10 degrees or greater. Scoliosis may be classified as either structural (fixed, nonflexible) or nonstructural (flexible, correctable).

Recurrent depressive episodes during autumn and winter alternating with nondepressive episodes during spring and summer. Patients with seasonal affective disorder (SAD) have experienced two episodes of major depression in the past 2 yr that demonstrate the temporal seasonal relations and have had no nonseasonal episodes over this period.

Mild to severe rash characterized by scaling and erythema that occurs in areas of the skin rich in sebaceous glands.

Absence seizures are a type of generalized seizures, characterized by brief episodes of staring with impairment of consciousness (absence). They usually last a few seconds up to 20 to 30 sec. The onset and the end of the seizures are sudden. Usually the patients are not aware of them and resume the activity they were doing prior to the seizure. The electroencephalogram signature of absence seizures consists of generalized 3-Hz spike and slow wave discharges.

Febrile seizures are seizures that occur in febrile children between the ages of 6 and 60 mo who do not have an intracranial infection, metabolic disturbance, or history of a febrile seizure. Febrile seizures are subdivided into 2 categories: simple and complex. Simple febrile seizures last <15 min, are generalized (without a focal component), and occur once in a 24-hr period, whereas complex febrile seizures are prolonged (>15 min), show focal neurologic signs, or occur more than once in 24 hr.

Tonic clonic seizures are characterized by sudden loss of consciousness, muscle contraction (tonic phase) followed by rhythmic jerking activity (clonic phase).

Partial seizures are characterized by focal cortical discharges that provoke seizure symptoms related to the area of the brain involved. Simple partial seizures do not cause impairment of consciousness.

Septicemia is a systemic illness caused by generalized bacterial or fungal infection and characterized by evidence of infection, fever or hypothermia, hypotension, and evidence of endorgan compromise.

Serotonin syndrome (SS) refers to a group of symptoms resulting from increased activity of serotonin (5-hydroxytryptamine) in the CNS. SS is a drug-induced disorder that is classically characterized by a change in mental status and alteration in neuromuscular activity and autonomic function.

Severe acute respiratory syndrome (SARS) is a respiratory illness caused by a coronavirus called SARS-associated coronavirus (SARSCoV)

• A sexual dysfunction in a woman is any disorder that interferes with female sexuality and that causes marked distress to that person. These disorders are generally categorized into four types:
• 1. Disorders of desire (most common)
• 2. Disorders of arousal
• 3. Orgasmic disorders
• 4. Sexual pain disorders (including dyspareunia, vaginismus, and vulvodynia)
• Female sexual dysfunction is also further categorized as lifelong (primary) or acquired (secondary), situational (e.g., current partner) or generalized (all partners and settings).

Sheehan's syndrome is a state of hypopituitarism resulting from an infarct of the pituitary secondary to postpartum hemorrhage or shock, causing partial or complete loss of the anterior pituitary hormones (adrenocorticotropic hormone [ACTH], follicle-stimulating hormone [FSH], luteinizing hormone [LH], growth hormone [GH], prolactin [PRL], thyroid-stimulating hormone [TSH]) and their target organ functions.

Shigellosis is an inflammatory disease of the bowel caused by one of several species of Shigella. It is the most common cause of bacillary dysentery in the U.S.

Short bowel syndrome is a malabsorption syndrome that results from extensive small intestinal resection.

Sialadenitis is an inflammation of the salivary glands.

Sialolithiasis is the existence of hardened intraluminal deposits in the ductal system of a salivary gland.

• Sick sinus syndrome is a group of cardiac rhythm disturbances characterized by abnormalities of the sinus node including:
• (1) sinus bradycardia,
• (2) sinus arrest or exit block,
• (3) combinations of sinoatrial or atrioventricular conduction defects, and
• (4) alternating with paroxysmal supraventricular tachyarrhythmias (bradycardia-tachycardia syndrome) that result in atrial rates that are inappropriate for physiologic needs.

Sickle cell disease is a hemoglobinopathy characterized by the production of hemoglobin S caused by substitution of the amino acid valine for glutamic acid in the sixth position of the gamma-globin chain. When exposed to lower oxygen tension, red blood cells (RBCs) assume a sickle shape, resulting in stasis of RBCs in capillaries. Painful crises are caused by ischemic tissue injury resulting from obstruction of blood flow produced by sickled erythrocytes. Vasoocclusive crises are the main reason for hospital admission of children with SCD.

Silicosis is a lung disease attributable to the inhalation of silica (silicon dioxide) in crystalline form (quartz) or in cristobalite or tridymite forms.

• Sinusitis is inflammation of the mucous membranes lining one or more of the paranasal sinuses. The various presentations are:
• � Acute sinusitis: infection lasting ,4 wk, with complete resolution of symptoms.
• � Subacute infection: lasts from 4 to 12 wk, with complete resolution of symptoms.
• � Recurrent acute infection: episodes of acute infection lasting ,30 days, with resolution of symptoms, which recur at intervals at least 10 days apart.
• � Chronic sinusitis: inflammation lasting .12 wk, with persistent upper respiratory symptoms.
• � Acute bacterial sinusitis superimposed on chronic sinusitis: new symptoms that occur in patients with residual symptoms from prior infection(s). With treatment, the new symptoms resolve but the residual ones do not.

• Sjogren's syndrome (SS) is an autoimmune disorder characterized by lymphocytic and plasma cell infiltration and destruction of salivary and lacrimal glands with subsequent diminished lacrimal and salivary gland secretions.
• � Primary: dry mouth (xerostomia) and dry eyes (xerophthalmia) develop as isolated entities.
• � Secondary: associated with other disorders.

The International Classification of Sleep Disorders, Second Edition, classifies sleep-disordered breathing disorders into three categories: central sleep apnea syndrome, obstructive sleep apnea (OSA), and sleep-related hypoventilation/ hypoxic syndromes. The American Academy of Sleep Disorders defines OSA as repetitive episodes of upper airway obstruction that occur during sleep and that are typically associated with oxyhemoglobin desaturations.

Smallpox infection is caused by the variola virus, a DNA virus member of the genus Orthopoxvirus. It is a human virus with no known nonhuman reservoir of disease. Natural infection occurs after implantation of the virus on the oropharyngeal or respiratory mucosa.

• Social anxiety disorder (SAD) is a persistent and significant fear of being embarrassed or humiliated in social and/or performance situations. SAD commonly presents as excessive anxiety or fear in situations involving social interactions (e.g., conversing with one or a group of other individuals, with sexually attractive others, with authority figures) and/or performance situations (e.g., public speaking, acting/performing in front of an audience). The anxiety must persist in these situations for at least 6 mo in individuals younger than age 18. The anxiety often results in avoidance of these situations, thus leading to significant occupational, academic, and/or social impairment as well as marked distress.
• Currently two subtypes are described: specific (fear of one or only a few situations) and generalized (fear of many social situations).

Somatization disorder refers to a pattern of recurring multiple somatic complaints that begin before the age of 30 yr and persist over several years. Patients complain of multiple sites of pain (a minimum of four), gastrointestinal symptoms (a minimum of two), a sexual or reproductive symptom, and a pseudoneurologic symptom. These cannot be explained by a medical condition or are in excess of an expected disability from a coexisting medical condition.

Exaggerated tone, which displays a velocitydependent increase in resistance of muscles to a passive stretch stimulus.

• Spina bifida is the term for a group of neural tube disorders that involve the spinal column, including spina bifida occulta and spina bifida cystica. Anencephaly and cranium bifidum (i.e., encephalocele) are also classified as neural tube disorders, but these involve the cranium and brain and thus deserve a separate classification.
• Spina bifida occulta is a midline defect that involves the closure of the posterior vertebral arches and laminae and that usually involves the L5-S1 area of the spinal cord.
• Spina bifida cystica involves both meningocele and myelomeningocele.
• Meningocele is a midline defect in which meninges herniate through the posterior vertebral arch defect with a normal spinal cord in a normal position in the spinal canal; this condition makes up about 5% of cases of spina bifida cystica. Myelomeningocele is the most severe form of disease in the spectrum of spina bifida. The meninges, fragments of bone and cartilage, and the spinal cord herniate through the vertebral arches or the skin; this condition makes up about 95% of cases. The majority of these defects (,75%) are located in the lumbosacral area.

• Spinal cord compression is the neurologic loss of spine function. Lesions may be complete or incomplete and develop gradually or acutely. Incomplete lesions often present as distinct syndromes, as follows:
• � Central cord syndrome
• � Anterior cord syndrome
• � Brown-Sequard syndrome
• � Conus medullaris syndrome
• � Cauda equina syndrome

A spinal epidural abscess (SEA) is a focal suppurative infection occurring in the spinal epidural space.

Spinal stenosis is the pathologic condition caused by the compressing or narrowing of the spinal canal, nerve root canal, or intervertebral foramina at the lumbar region.

The spinocerebellar ataxias (SCAs) are a heterogeneous group of autosomal dominantly inherited genetic conditions that cause progressive ataxia.

• Spontaneous miscarriage is fetal loss before week 20 of pregnancy, calculated from the patient's last menstrual period or the delivery of a fetus weighing <500 g.
• Early loss is before menstrual week 12, whereas late loss refers to losses from weeks 12 to 20.
• Miscarriage can also be classified as incomplete (partial passage of fetal tissue through partially dilated cervix), complete (spontaneous passage of all fetal tissue), threatened (uterine bleeding without cervical dilation or passage of tissue), inevitable (bleeding with cervical dilation without passage of fetal tissue), or missed abortion (intrauterine fetal demise without passage of tissue).
• Recurrent miscarriage involves three or more spontaneous pregnancy losses before week 20.

Sporotrichosis is a granulomatous disease caused by the dimorphic fungus Sporothrix schenckii.

• Complex pathophysiological process affecting the brain, induced by traumatic biomechanical forces. It may be caused by a direct blow to the head, face, neck, or elsewhere on the body with an "impulsive"force transmitted to the head.
• � Concussion typically results in the rapid onset of short-lived impairment of neurologic function that resolves spontaneously. It may result in neuropathologic changes, but the acute clinical symptoms largely reflect a functional disturbance rather than a structural injury.
• � Concussion results in a graded set of clinical syndromes that may or may not involve loss of consciousness. Resolution of the clinical symptoms typically follows a sequential course. It is typically associated with grossly normal structural neuroimaging studies.

Squamous cell carcinoma (SCC) is a malignant tumor of the skin arising in the epithelium.

Stasis dermatitis refers to an inflammatory skin disease of the lower extremities, commonly seen in patients with chronic venous insufficiency.

Status epilepticus is a medical neurologic emergency. It is historically defined as 30 min of continuous seizure activity or two or more seizures without full recovery of consciousness between seizures. However, in practice a continuous seizure that last >5 min may be considered and treated as status epilepticus.

Stevens-Johnson syndrome (SJS) is a rare, severe vesiculobullous form of erythema multiforme affecting the skin, mouth, eyes, and genitalia.

Stomatitis is inflammation involving the oral mucous membranes.

Strabismus is a condition of the eyes in which the visual axes of the eyes are not straight in the primary position or in which the eyes do not follow each other in the different positions of gaze.

Ischemic stroke is the sudden onset of a focal neurologic deficit as a result of ischemia. Acute ischemic stroke may be defined as relating to the first few days after onset. However, the purpose of this chapter is to help the provider to make decisions regarding the acute stroke patient within the first several hours of symptoms; this is the crucial time for definitive treatment interventions.

Hemorrhagic stroke is the sudden onset of a focal neurologic deficit caused by hemorrhage into or around the brain.

Secondary prevention of stroke involves preventing the recurrence of a cerebral vascular ischemic or hemorrhagic stroke after a primary event.

Sturge-Weber syndrome (SWS) is a sporadic congenital disorder characterized by a dermal capillary malformation (port-wine stain) occurring in association with vascular malformations of the leptomeninges and the eye. Sturge first described a patient with epilepsy, a facial capillary malformation, and buphthalmos in 1879. Parkes Weber better characterized the pattern and distribution of the characteristic intracranial calcifications. The complete syndrome generally includes the triad of facial dermal capillary malformation (port-wine stain), ipsilateral central nervous system (CNS) vascular malformation (leptomeningeal angiomatosis), and vascular malformation of the choroid of the eye associated with glaucoma. Partial forms have been reported.

Subarachnoid hemorrhage (SAH) is defined as hemorrhage into the subarachnoid space. There are several causes of SAH, with the most common being head trauma and the rupture of an intracerebral aneurysm.

Subclavian steal syndrome is an occlusion or severe stenosis of the proximal subclavian artery leading to decreased antegrade flow or retrograde flow in the ipsilateral vertebral artery and neurologic symptoms referable to the posterior circulation.

A subdural hematoma (SDH) is a collection of blood or blood products between the arachnoidal (superficial) layer of the brain and the dura or meningeal layer of the brain.

Suicide is the intentional ending of one's own life.

Superior vena cava syndrome is a set of symptoms that results when a mediastinal mass compresses the superior vena cava (SVC) or the veins that drain into it.

Syncope is the transient loss of consciousness that results from an acute global reduction in cerebral blood flow. Syncope should be distinguished from other causes of transient loss of consciousness..

Syndrome of inappropriate antidiuresis (SIAD) is a syndrome characterized by excessive secretion of antidiuretic hormone (ADH) in absence of normal osmotic or physiologic stimuli (increased serum osmolarity, decreased plasma volume, hypotension).

Syphilis is a systemic sexually transmitted treponemal disease, acute and chronic, characterized by primary skin lesions; secondary eruption involving skin and mucous membranes; long periods of latency; and late lesions of the skin, bone, viscera, central nervous system, and cardiovascular system.

Syringomyelia is a disease of the spine characterized by the formation of fluid-filled cavities within the spinal cord, sometimes extending into the brain stem.

Systemic lupus erythematosus (SLE) is a chronic, multisystemic disease characterized by production of autoantibodies and protean clinical manifestations.

Q fever is a systemic febrile illness caused by Coxiella burnetii that may be acute or chronic.

Zenker's diverticulum (ZD) refers to the acquired physiologic obstruction of the esophageal introitus that results from mucosal herniation posteriorly between the cricopharyngeus muscle and the inferior pharyngeal constrictor muscle.

Zollinger-Ellison (ZE) syndrome is a hypergastrinemic state caused by a pancreatic or extrapancreatic non-beta islet cell tumor (gastrinoma) resulting in peptic acid disease.

Babesiosis is a tick-transmitted protozoan disease of animals, caused by intraerythrocytic parasites of the genus Babesia. Humans are incidentally infected, resulting in a nonspecific febrile illness. The disease can be severe in immunocompromised hosts.

Baker's cyst is a fluid-filled popliteal bursa located along the medial border of the popliteal fossa.

Balanitis is an inflammation of the superficial tissues of the penile head.

Barrett's esophagus occurs when the squamocolumnar junction is displaced proximal to the gastroesophageal junction, and the squamous liningof the lower esophagus is replaced by metaplastic columnar epithelium, which predisposes to the development of cancer. Intestinalized epithelium is no longer considered essentialfor the diagnosis. The condition is associated with an increased risk (~0.5%/yr) for development of adenocarcinoma of the esophagus.

Bartter's syndrome is a group of renal tubular disorders characterized by metabolic alkalosis, hypokalemia, hyperplasia of the juxtaglomerular apparatus, hyperreninemic hyperaldosteronism, and hypercalciuria.

Basal cell carcinoma (BCC) is a malignant tumor of the skin arising from basal cells of the lower epidermis and adnexal structures. It may be classified as one of six types: nodular, superficial, pigmented, cystic, sclerosing or morpheaform, and nevoid. The most common type is nodular (21%); the least common is morpheaform (1%). A mixed pattern is present in approximately 40% of cases. BCC advances by direct expansion and destroys normal tissue.

A bedbug's bite is a wound caused by the penetration of the bedbug mouthpiece into the skin as the insect feeds on blood from vessels or extravasated blood from the damaged surrounding tissue. The saliva of the bedbug contains pharmacologically active substances responsible for a spectrum of undesirable skin reactions depending on the individual.

Behcet's disease is a chronic, relapsing, inflammatory disorder characterized by the presence of recurrent oral aphthous ulcers, genital ulcers, uveitis, and skin lesions.

Acute peripheral facial (seventh) nerve palsy

This is a common cause of anterior shoulder pain characterized by an inflammatory process that involves the long head of the biceps tendon as well as its sheath within the bicipital groove. The tendon involvement can be intra-articular from its attachment to the superior glenoid labrum as it runs across the glenohumeral joint and extra-articular as it runs in the bicipital or intertubercular groove.

• Bipolar disorder is an episodic, recurrent, frequently progressive condition in which the afflicted individual experiences at least one episode of mania, characterized by at least 1 wk of continuous symptoms of elevated, expansive, or irritable mood, in association with three or four of the following symptoms:
• � Decreased need for sleep
• � Grandiosity
• � Pressured speech
• � Subjective or objective flight of ideas
• � Distractibility
• � Increased level of goal-directed activity
• � Problematic behavior Most individuals with bipolar disorder also experience one or more episodes of major depression over their lifetimes or have symptoms of a depressive episode commingled with those of mania (mixed episode).

A bite wound can be animal or human, accidental or intentional.

• There are two major classes of arthropods: insects and arachnida. Focus on the class arachnida. Arachnid bites consist of bites caused by:
• � Spiders
• � Scorpions
• � Ticks

• Most stinging insects belong to the Hymenoptera order and include yellow jackets (most common cause of reactions), hornets, bumblebees, sweat bees, wasps, harvester ants, fire ants, and the Africanized honey bee ("killer bee"). Brown recluse spiders, although not insects, are another common cause of bites.
• The usual effect of a sting is intense local pain, some immediate erythema, and often a small area of edema from the injecting venom. Allergic reactions can be either local or generalized, leading to anaphylactic shock. The majority of reactions occur within the first 6 hr after the sting or bite, but a delayed presentation may occur up to 24 hr.

Injury resulting from snake biting a human.

Bladder cancer is a heterogeneous spectrum of neoplasms ranging from non-life-threatening, low-grade, superficial papillary lesions to high grade invasive tumors, which often have metastasized at the time of presentation. It is a field change disease in which the entire urothelium from the renal pelvis to the urethra may be susceptible to malignant transformation. The three types of bladder cancer are transitional cell carcinoma (TCCa), squamous cell carcinoma, and adenocarcinoma.

Blastomycosis is a systemic pyogranulomatous disease caused by a dimorphic fungus, Blastomyces dermatitidis.

Blepharitis is an acute or, most often, chronic inflammation of the eyelid margins that is often refractory to treatment.

Body dysmorphic disorder (BDD) is a somatoform disorder characterized by preoccupation with a slight or imagined defect in physical appearance that causes clinically significant distress or impairment in social, occupational, or other important areas of functioning. The appearance preoccupations are not restricted to concerns with body fat or weight in an individual with an eating disorder.

• Primary malignant bone tumors are invasive and anaplastic and have the ability to metastasize. Most arise from the marrow (myeloma), but tumors may develop from bone, cartilage, fat, and fibrous tissues. Leukemia and lymphoma are excluded from this discussion.
• FIBROSARCOMA AND LIPOSARCOMA: Extremely rare. They are similar to tumors arising in soft tissue.
• OSTEOSARCOMA: A rare primary malignant tumor of bone characterized by malignant tumor cells that produce osteoid or bone. Several variants have been described: parosteal sarcoma, periosteal sarcoma, multicentric, and telangiectatic forms.
• CHONDROSARCOMA: A malignant cartilage tumor that may develop primarily or secondarily from transformation of a benign osteocartilaginous exostosis or enchondroma.
• EWING'S SARCOMA: A malignant tumor of unknown histogenesis.
• MULTIPLE MYELOMA: A neoplastic proliferation of plasma cells.

• Borderline personality disorder (BPD) is characterized by a pervasive pattern of instability in interpersonal relationships, self-image, affect regulation, and impulse control that causes significant subjective distress or impairment of functioning. The individual must meet five or more of the following criteria:
• 1. Frantic efforts to avoid real or imagined abandonment
• 2. Unstable and intense personal relationships characterized by alternating between extremes of idealization and devaluation
• 3. Identity disturbance characterized by an unstable self-image
• 4. Impulsivity in at least two areas that are potentially self-damaging (e.g., overspending, sex, substance abuse, binge eating, reckless driving)
• 5. Recurrent suicidal behavior, gestures, threats, or self-mutilating behavior
• 6. Affective instability due to a marked reactivity of mood
• 7. Chronic feelings of emptiness
• 8. Inappropriate, intense anger or difficulty controlling anger
• 9. Transient, stress-related paranoid ideation or severe dissociative symptoms

Botulism is an illness caused by a neurotoxin produced by Clostridium botulinum. Three types of disease can occur: foodborne botulism, wound botulism, and infant intestinal botulism. Recent concern has increased about a possible fourth type of disease: inhalational botulism, which does not occur naturally, but may occur as a result of bioterrorism.

Brain metastases spread to the brain from cancer originating in other organs. Brain metastases are the most common intracranial tumors in adults and account for more than one half of brain tumors.

Brain neoplasms are a diverse group of primary (nonmetastatic) tumors arising from one of many different cell types within the central nervous system (CNS). Specific tumors subtypes and prognosis depend on the tumor cell of origin and pattern of growth.

Brain neoplasms are a diverse group of primary (nonmetastatic) tumors arising from one of the many different cell types within the central nervous system. Malignant brain tumors are defined by histopathologic features and a rapidly progressive pattern of growth. Glioblastoma is the most common primary brain tumor in adults, accounting for 50% to 60% of primary brain tumors.

The term breast cancer refers to invasive carcinoma of the breast, whether ductal or lobular.

Breech presentation occurs when the fetal longitudinal axis is such that the cephalic pole occupies the uterine fundus. Three types exist, with respective percentages at term: frank (48% to 73%, flexed hips, extended knees), complete (4.6% to 11.5%, flexed hips and knees), and footling (12% to 38%, hips extended).

Bronchiectasis is the abnormal dilation and destruction of bronchial walls, which may be congenital or acquired.

Brucellosis is a zoonotic infection caused by one of four species of Brucella. It commonly presents as a nondescript febrile illness.

Genetic disease characterized by a specific electrocardiogram (ECG) pattern and increased risk of sudden cardiac death (SCD) in individuals with structurally normal hearts.

Forcible clenching or grinding of the teeth during sleep or wakefulness, often leading to damage of the teeth.

Budd-Chiari syndrome (BCS) is a rare disease defined by the obstruction of hepatic venous outflow anywhere from the small hepatic veins to the junction of the inferior vena cava (IVC) and the right atrium. Primary BCS is defined by endoluminal obstruction as seen in thromboses or webs. Secondary BCS occurs when the obstruction is caused by compression or invasion by a lesion originating outside the veins (tumor, abscess, cyst, etc.). It can also be a postoperative complication of orthotopic liver transplantation.

Bulimia nervosa is a prolonged illness characterized by a specific psychopathology.

Bullous pemphigoid is an autoimmune, subepidermal blistering disease commonly seen in the elderly. A related entity is cicatricial pemphigoid, which predominantly affects the mucous membranes.

Burning mouth syndrome (BMS) is characterized by burning pain in the tongue or oral mucous membranes, usually occurring without any identifiable precipitating factor. Affected patients may also complain about bitter or metallic taste, dry mouth, and alterations in taste.

Burn injuries include thermal injuries (flames, scalds, cigarettes), as well as chemical, electrical, and radiation burns.

Bursitis is an inflammation of a bursa and is usually aseptic. A bursa is a closed sac lined with a synovial-like membrane that sometimes contains fluid that is found or that develops in an area subject to pressure or friction.

• Abruptio placentae is the separation of placenta from the uterine wall before delivery of the fetus. There are three classes of abruption based on maternal and fetal status, including an assessment of uterine contractions, quantity of bleeding, fetal heart rate monitoring, and abnormal coagulation studies (fibrinogen, prothrombin time, partial thromboplastin time).
• � Grade I: mild vaginal bleeding, uterine irritability, stable vital signs, reassuring fetal heart rate, normal coagulation profile (fibrinogen 450 mg%)
• � Grade II: moderate vaginal bleeding, hypertonic uterine contractions, orthostatic blood pressure measurements, unfavorable fetal status, fibrinogen 150 to 250 mg%
• � Grade III: severe bleeding (may be concealed), hypertonic uterine contractions, overt signs of hypovolemic shock, fetal death, thrombocytopenia, fibrinogen <150 mg%

A brain abscess is a focal, intracerebral infection that begins as a localized area of cerebritis and develops into a collection of pus surrounded by a well-vascularized capsule.

Breast abscess is an acute inflammatory process resulting in the formation of a collection of purulent material. Typically there is painful erythematous mass formation in the breast, occasionally draining through the overlying skin or nipple duct.

Liver abscess is a necrotic infection of the liver usually classified as pyogenic or amebic.

A lung abscess is an infection of the lung parenchymaresulting in a necrotic cavity containing pus.

• Pelvic abscess is an acute or chronic infection, most commonly involving the pelvic viscera. Treatment and possible cure require directed therapy that will involve antibiotic therapy and, if medical therapy fails, subsequent surgical therapy. There are four categories based on etiologic factors:
• � Ascending infection, spreading from cervix through endometrial cavity to adnexa, forming a tuboovarian complex
• � Infection occurring in the puerperium, which spreads to the adnexa from the endometrium or myometrium by a hematogenous or lymphatic route
• � Abscess complicating pelvic surgery
• � Involvement of the pelvic viscera as a result of spread from contiguous organs, such as appendicitis or diverticulitis

A perirectal abscess is a localized inflammatory process that can be associated with infections of soft tissue and anal glands based on anatomic location. Perianal and perirectal abscesses may be simple or complex, causing suppuration. Infections in these spaces may be classified as superficial perianal or perirectal with involvement in the following anatomic spaces: ischiorectal, intersphincteric, perianal, and supralevator.

• Definition from the Federal Child Abuse Prevention and Treatment Act (CAPTA): any recent act or failure to act on the part of a parent or caretaker that results in death, serious physical or emotional harm, sexual abuse or exploitation of a child; or an act or failure to act which presents an imminent risk of serious harm to a child.
• � Neglect: failure to provide for the basic needs of a child
• 1. Physical neglect: failure to provide necessary food, shelter, and supervision
• 2. Medical neglect: failure to provide necessary medical or mental health care
• 3. Educational neglect: failure to meet educational needs
• 4. Emotional neglect: failure to attend to emotional needs, exposure to domestic violence
• � Physical abuse: physical injury inflicted by a parent or caregiver intentionally or in the course of excessive discipline
• � Sexual abuse: sexual act inflicted by parent or caretaker; includes exploitation and pornography
• � Emotional abuse: pattern of behavior of caretaker toward a child that impairs emotional development. This includes verbal abuse, cruelty, and threats.

Drug abuse is a recurring pattern of harmful use of a substance despite adverse consequences to work, school, relationships, the legal system, or personal health. This may occur concurrently with or independently from substance dependence, in which the impairment or distress is more pervasive and often (though not necessarily) includes physical dependence and withdrawal symptoms.

• Elder abuse includes abuse commited by someone in a trust relation whether in the community or institutional setting.
• � Physical abuse: inflicting physical pain or injury
• � Sexual abuse: inflicting nonconsensual sexual activity
• � Psychological abuse: inflicting mental anguish, including intimidation, humiliation, or threats
• � Financial abuse: improper use of resources, property, or assets without the person's consent
• � Neglect: abandonment, failure to fulfill a care-taking obligation, including provision of food, safe shelter, physical health and mental health care, or basic custodial care

Acetaminophen (APAP) poisoning is a disorder caused by excessive intake of acetaminophen and is manifested by jaundice, nausea, vomiting, and potential death from hepatic necrosis if not treated appropriately.

Achalasia is a motility disorder of the esophagus classically characterized by incomplete relaxation of the lower esophageal sphincter (LES) and aperistalsis of esophageal smooth muscle. The result is functional obstruction of the esophagus.

Achilles tendon rupture refers to the loss of continuity of the tendo Achillis, usually from attrition.

• Acne vulgaris is a chronic disorder of the apparatus caused by abnormal desquamation of follicular epithelium leading to obstruction of the pilosebaceous canal, resulting in inflammation and subsequent formation of papules, pustules, nodules, comedones, and scarring. Acne can be classified by the type of lesion (comedonal, papulopustular, and nodulocystic). The American Academy of Dermatology classification scheme for acne denotes the following three levels:
• 1. Mild acne: characterized by the presence of
• comedones (noninflammatory lesions), few papules and pustules (generally <10), but no nodules.
• 2. Moderate acne: presence of several to many papules and pustules (10 to 40) along with comedones (10 to 40). The presence of >40 papules and pustules along with larger, deeper nodular inflamed lesions (up to five) denotes moderately severe acne.
• 3. Severe acne: presence of numerous or extensive papules and pustules as well as many nodular lesions.

Acoustic neuroma is a benign proliferation of the Schwann cells that cover the vestibular branch of the eighth cranial nerve (CN VIII). Symptoms are commonly a result of compression of the acoustic branch of CN VIII, the facial nerve (CN VII), and the trigeminal nerve (CN V). The glossopharyngeal nerve (CN IX) and vagus nerve (CN X) are less commonly involved. In extreme cases compression of the brain stem may lead to obstruction of cerebrospinal fluid (CSF) outflow and elevated intracranial pressure (ICP).

Acquired immunodeficiency syndrome (AIDS) is a disorder caused by infection with the human immunodeficiency virus, type 1 (HIV-1), and marked by progressive deterioration of the cellular immune system, leading to secondary infections or malignancies.

Acromegaly occurs due to hypersecretion of growth hormone (GH) or increased amounts of insulin-like growth factor I (IGF-I). It is a chronic debilitating disease with an insidious onset.

Actinomycosis is an indolent, slowly progressive infection caused by both anaerobic or microaerophilic bacteria that normally colonize the mouth, vagina, and colon. Actinomycosis is characterized by the formation of painful abscesses, soft tissue infiltration, and draining sinuses.

Acute bronchitis is the inflammation of trachea and bronchi.

Acute coronary syndrome (ACS) represents a spectrum of clinical disorders that include unstable angina (UA), non ST-elevation myocardial infarction (NSTEMI), and ST-elevation myocardial infarction (STEMI). While the severity of disease will vary between the three subsets of ACS, they all share a common clinical presentation and pathophysiology. This syndrome is typically caused by atherosclerotic coronary artery disease (CAD). In this spectrum, UA and NSTEMI are represented electrocardiographically by ST-segment depression and T-wave inversion in the appropriate clinical setting (i.e., chest discomfort). NSTEMI would have the addition of positive cardiac biomarkers. STEMI is represented by ST-segment elevation. ACS should be thought of as a continuous spectrum as UA will often progress to a myocardial infarction if left untreated.

• Acute respiratory distress syndrome (ARDS) is a form of noncardiogenic pulmonary edema that results from acute damage to the alveoli. It is characterized by acute diffuse infiltrative lung lesions with resulting interstitial and alveolar edema, severe hypoxemia, and respiratory failure. The definition of ARDS includes the following three components:
• 1. A ratio of Pao2 to Fio2 <or=200 regardless of the level of positive end expiratory pressure (PEEP)
• 2. The detection of bilateral pulmonary infiltrates on frontal chest radiograph
• 3. Absence of congestive heart failure (pulmonary artery wedge pressure [PAWP] <18 mm Hg or no clinical evidence of elevated left atrial pressure on the basis of chest radiograph or other clinical data) The cardinal feature of ARDS, refractory hypoxemia, is caused by formation of protein-rich alveolar edema after damage to the integrity of the lung's alveolar-capillary barrier.

Addison disease is characterized by inadequate secretion of corticosteroids resulting from partial or complete destruction of the adrenal glands.

• Although defining alcoholism precisely is impossible, among the commonly used screening instruments for this disorder are the CAGE questionnaire, short Michigan Alcoholism Screening Test (SMAST), National Council on Alcoholism criteria, and DSM-IV-R criteria. Moderate drinking has been defined as two standard drinks (e.g., 12 oz of beer) per day and one drink per day for women and persons older than 65 yr. Although not generally included under the alcoholism topic, hazardous or at-risk drinking should also be considered. For men, at-risk drinking is defined as more than 14 drinks/wk or more than 4 drinks/occasion. For women, at-risk drinking is defined as approximately half that given for men. The American Psychiatric Association defines diagnostic criteria for alcohol withdrawal as follows:
• A. Cessation of (or reduction in) alcohol use that has been heavy and prolonged.
• B. Two (or more) of the following, developing within several hours to a few days after criterion
• A:
• 1. Autonomic hyperactivity (e.g., sweating or pulse rate >100 beats/min)
• 2. Increased hand tremor
• 3. Insomnia
• 4. Nausea and vomiting
• 5. Transient visual, tactile, or auditory hallucinations or illusions
• 6. Psychomotor agitation
• 7. Anxiety
• 8. Grand mal seizures
• C. The symptoms in criterion B cause clinically significant distress or impairment in social, occupational, or other important areas of functioning.
• The symptoms are not attributable to a general medical condition and are not better accounted for by another mental disorder.

Alopecia is the term used to describe involuntary hair loss, typically on the scalp or beard, but possibly over the entire body. Nonscarring alopecia is hair loss without clinically apparent scarring, inflammation, or skin atrophy. Scarring alopecia is characterized by hair loss accompanied by tissue destruction in the form of scarring, inflammation, and/or skin atrophy.

Alpha-1-antitrypsin deficiency is a genetic deficiency of the protease inhibitor alpha-1-antitrypsin that results in a predisposition to pulmonary emphysema and hepatic cirrhosis.

Altitude sickness refers to a spectrum of illnesses related to hypoxemia occurring during rapid ascension to high altitudes. Common acute syndromes occurring at high altitudes include acute mountain sickness (AMS), high altitude pulmonary edema (HAPE), and hig haltitude cerebral edema (HACE).

Dementia is a syndrome characterized by progressive loss of previously acquired cognitive skills including memory, language, insight, and judgment. Alzheimer's disease (AD) is believed to account for the majority (50% to 75%) of all cases of dementia.

Amaurosis fugax (AF) is a temporary loss of monocular vision caused by transient retinal ischemia..

Amblyopia refers to a decrease in vision in one or both eyes in the presence of an otherwise normal ophthalmologic examination.

Amebiasis is an infection caused by the protozoal parasite Entamoeba histolytica. Althoug primarily an infection of the colon, amebiasis may cause extraintestinal disease, particularly liver abscess.

• Amenorrhea means absence of menstruation. It is classified as either primary or secondary depending on whether the patient has had previous menstrual cycles.
• � Primary amenorrhea is defined as the absence of menses by age 16 in the presence of secondary sexual characteristics. However, in the absence of these secondary sexual features by the age of 13 to 14 years, one should begin the workup for primary amenorrhea.
• � Secondary amenorrhea is the absence of menses for more than six months in a patient who has had previous normal progesterone withdrawal cycles.

The acquired inability to learn new, or recall previously learned information. The impairment compromises social and occupational functioning. It is caused by an identifiable medical condition or by persisting effects of a substance. Disorder is not caused by delirium or dementia. It may be transient or chronic.

• The term amyloidosis refers to a heterogenous group of disorders that are all characterized by the deposition of an amorphous, extracellular fibrillar protein in various organs and tissues of the body. It has the following subtypes:
• � Primary amyloidosis (AL)
• � Secondary amyloidosis (AA)
• � Hereditary amyloidosis
• � Localized amyloidosis

Amyotrophic lateral sclerosis (ALS) is a progressive, degenerative neuromuscular condition of undetermined etiology affecting corticospinal tracts and anterior horn cells, resulting in dysfunction of both upper motor neurons (UMN) and lower motor neurons (LMN), respectively.

An anaerobic infection is caused by one of a group of bacteria that requires a reduced oxygen tension for growth.

A fissure is a tear in the epithelial lining of the anal canal (i.e., from the dentate line to the anal verge).

Anaphylaxis is a sudden-onset, life-threatening event characterized by bronchospasm in conjunction with hemodynamic changes. Its clinical presentation may include respiratory, cardiovascular, and cutaneous manifestations.

The anemia of chronic disease refers to mild to moderately severe anemias (with hemoglobin [Hb] ranging from 7-12 g/dl), associated with chronic infections and inflammatory disorders, and some malignancies. Anemia of chronic disease may also refer to normal total body iron stores with low circulating iron (<60 mcg/dl).

Aplastic anemia is a bone marrow failure syndrome defined by peripheral blood pancytopenia and hypocellular bone marrow.

Autoimmune hemolytic anemia (AIHA) is anemia secondary to premature destruction of red blood cells (RBCs) caused by the binding of autoantibodies and/or complement to RBCs.

Iron deficiency anemia is anemia resulting from inadequate iron supplementation or excessive blood loss.

Pernicious anemia (PA) is an autoimmune disease resulting from antibodies against intrinsic factor and gastric parietal cells.

Sideroblastic anemia is a heterogenous group of blood disorders whose two distinctive features are ring sideroblasts in the bone marrow (abnormal erythroblasts with excessive iron accumulation in the mitochondria) and impaired heme biosynthesis. They are classified as hereditary, acquired, and reversible.

An abdominal aortic aneurysm (AAA) is a permanent localized dilation of the abdominal aortic artery to at least 1.5 times the diameter measured at the level of the renal arteries; or exceeding the normal diameter of the abdominal aorta by >50%. The normal diameter at the renal arteries is 2.0 cm (range, 1.4 to 3.0 cm), and a diameter >3.0 cm is generally considered aneurysmal.

• Angina pectoris is a term used to describe a syndrome, typically characterized by chest discomfort, that is caused by myocardial ischemia.This is most commonly related to atheromatous plaque in the coronary arteries; however, myocardial ischemia may occur in the absence of obstructive CAD. Any situation that causes an imbalance in myocardial oxygen supply anddemand can cause an angina syndrome. Myocardial ischemia can be asymptomatic (silent ischemia), particularly in diabetics. Angina can be classified as follows:
• 1.Chronic (stable)
• 2.Unstable
• 3.Prinzmetal's variant
• 4.Microvascular (Syndrome X)
• 5.Other
• 6.Refractory

• The mucocutaneous swelling caused by the release of vasoactive mediators is called urticaria and angioedema.
• � Urticaria causes edema of the superficial dermis.
• � Angioedema involves the deep layers of the dermis and the subcutaneous tissue.

Ankle fractures involve the lateral, medial, or posterior malleolus of the ankle and may occur either alone or in some combination. Associated ligamentous injuries are included.

An ankle sprain is an injury to the ligamentous support of the ankle. Most (85%) involve the lateral ligament complex. The anterior inferior tibiofibular (AITF) ligament, deltoid ligament, and interosseous membrane may also be injured. Damage to the tibiofibular syndesmosis is sometimes called a high sprain because of pain above the ankle.

Ankylosing spondylitis is a type of inflammatory arthritis involving the sacroiliac joints and axial skeleton characterized by ankylosis and enthesitis (inflammation at tendon insertions). It is one of a family of overlapping syndromes called seronegative spondyloarthropathies that includes reactive arthritis (Reiter syndrome), psoriatic spondylitis, and enteropathic arthritis.i

• A fistula is an inflammatory tract with a secondary (external) opening in the perianal skin and a primary (internal) opening in the anal canal at the dentate line. It originates in an abscess in the intersphincteric space of the anal canal.
• Fistulas can be classified as follows:
• 1. Intersphincteric: fistula track passes within the intersphincteric plane to the perianal skin (most common)
• 2. Transsphincteric: fistula track passes from the internal opening, through the internal and external sphincter, and into the ischiorectal fossa to the perianal skin (frequent)
• 3. Suprasphincteric: after passing through the internal sphincter, fistula tract passes above the puborectalis and then tracts downward, lateral to the external sphincter, into the ischiorectal space to the perianal skin (uncommon); if abscess cavity extends cephalad, a supralevator abscess possibly palpable on rectal examination
• 4. Extrasphincteric: fistula tract passes from the rectum, above the levators, through the levator muscles to the ischiorectal space and perianal skin (rare)
• With a horseshoe fistula, the tract passes from one ischiorectal fossa to the other behind the rectum.

Anorexia nervosa is a psychiatric disorder characterized by abnormal eating behavior, severe self-induced weight loss, and a specific psychopathology.

Anoxic brain injury is cerebral ischemic injury due to decreased oxygen or blood flow to the brain typically caused by interruption of cardiac circulation or respiratory failure..

Anthrax is an acute infectious disease caused by the spore-forming bacterium Bacillus anthracis.

• The antiphospholipid antibody syndrome (APS) is characterized by arterial or venous thrombosis and/or pregnancy morbidity and the presence of at least one type of antiphospholipid antibody (aPL). aPL are antibodies directed against serum proteins bound to anionic phospholipids. Three types of aPL have been characterized:
• � Lupus anticoagulants
• � Anticardiolipin antibodies
• � Anti b2-glycoprotein-1 antibodies
• Primary APS occurs alone and secondary APS is in association with systemic lupus erythematosus (SLE), other rheumatic disorders, or certain infections or medications. APS can affect all organ systems and includes venous and arterial thrombosis, recurrent fetal losses, and thrombocytopenia.

Generalized anxiety disorder (GAD) is most likely to present in combination with other psychiatric and medical conditions. Individuals with GAD commonly present with excessive and disproportionately high levels of anxiety, fear, or worry for most days over at least a 6-mo period. The subjective anxiety must be accompanied by at least three somatic symptoms (e.g., restlessness, irritability, sleep disturbance, muscle tension, difficulty concentrating, or fatigability). GAD cannot be diagnosed if it occurs only in the setting of an active mood disorder, such as depression, or in the setting of an another active anxiety disorder, such as PTSD or panic disorder.t

Aortic dissection is part of a spectrum of aortic pathologies that include intramural hemtomasand penetrating atherosclerotic ulcers. Aortic dissection occurs when blood passes through an intimal tear, separating the intima from the medial layers and creating a false lumen. Intramural hematoma (IMH) occurs when the vasa vasorum ruptures within the medial wall. IMH does not involve an intimal tearing unless a dissection develops. One third of IMH will transform into aortic dissection. Penetrating atherosclerotic ulcers destroy the aortic intima and dissect into the aortic media,resulting in the formation of a pseudoaneurysm. Unlike aortic dissection, penetrating ulcers occur on the basis of extensive atherosclerosis in the aortic intima.

Aortic regurgitation is retrograde blood flow into the left ventricle from the aorta as a result of an incompetent aortic valve.

Aortic stenosis is obstruction to systolic left ventricular outflow across the aortic valve. Symptoms appear when the valve orifice decreases to <1 cm2 (normal orifice is 3 cm2). The stenosis is considered severe when the orifice is <0.5 cm2/ m2 or the pressure gradient is >=50 mm Hg.

Appendicitis is the acute inflammation of the appendix.

Arrhythmogenic right ventricular dysplasia (ARVD) is a disorder characterized by replacement of the normal myocardium by fibrofatty tissue, RV myocyte loss, and RV wall thinning. It is defined clinically by life-threatening ventricular arrhythmias in otherwise healthy young people.

The prototype of granulomatous arthritis is tuberculous arthritis. Atypical mycobacteria, sarcoidosis, and sporotrichosis can cause granulomatousinvolvement of the synovium, but these entities are much less common.

Bacterial arthritis is a highly destructive form of joint disease most often caused by hematogenous spread of organisms from a distant site of infection. Direct penetration of the joint as a osteomyelitis may also cause bacterial arthritis. Any joint in the body may be affected.

Psoriatic arthritis is an inflammatory arthropathy occurring in association with skin psoriasis and generally in the absence of rheumatoid factor. It is often included in a class of disorders called the seronegative spondyloarthropathies, a family of diseases characterized by inflammation of the spine, peripheral joints and enthesial sites. (sites of insertion of tendon into bone)

Asbestosis is a slowly progressive diffuse interstitial fibrosis resulting from dose-related inhalation exposure to fibers of asbestos.

Ascariasis is a parasitic infection caused by the nematode Ascaris lumbricoides. The majority of those infected are asymptomatic; however, clinical disease may arise from pulmonary hypersensitivity, intestinal obstruction, and secondary complications.

Ascites is the accumulation of excess fluid in the peritoneal cavity, most commonly caused by liver cirrhosis.

Aseptic necrosis is cell death in components of bone: hematopoietic fat marrow and mineralized tissue. Osteonecrosis is not a specific diseaseentity but a final common pathway to several disorders that impair blood supply to the femoral head and other locations.

Aspergillosis refers to several forms of a broad range of illnesses caused by infection with Aspergillus species.

The National Asthma Education and Prevention Program (NAEPP) guidelines define asthma as "a chronic inflammatory disease of the airways in which many cells and cellular elements play a role: in particular mast cells, neutrophils, eosinophils, T lymphocytes, macrophages, and epithelial cells. In susceptible individuals, this inflammation causes recurrent episodes of coughing (particularly at night or early in the morning), wheezing, breathlessness, and chest tightness. The episodes are usually associated with widespread but variable airflow obstruction that is reversible either spontaneously or as a result of treatment." Status asthmaticus can be defined as a severe continuous bronchospasm.

• Astrocytoma is a type of neuroepithelial tumor that arises from glial precursor cells (astrocytes, oligodendrocytes, ependymal cells, epithelial cells of the choroids plexus, and others). Astrocytoma arises from astrocytes within the central nervous system (CNS). They are commonly graded by the World Health Organization (WHO) or the Saint Anne-Mayo grading system. The WHO grades astrocytomas as follows:
• � Grade I: pilocytic astrocytoma
• � Grade II: low-grade astrocytoma (LGA), fibrillary infiltrating astrocytoma
• � Grade III: anaplastic astrocytoma
• � Grade IV: glioblastoma multiforme (GBM)
• � Grades III and IV are considered high-grade astrocytomas (HGAs) or malignant.
• Kernohan system grades astrocytomas based on histologic features: cellularity, mitoses, pleomorphism, vascularity, and necrosis. It has proved to be of prognostic value.
• � Grade I: increased cellularity
• � Grade II: greater cellularity than grade I plus pleomorphism
• � Grade III: greater cellularity and pleomorphism than grade II plus vascular proliferation
• � Grade IV: all the above, plus necrosis and pseudopalisading

Ataxia telangiectasia (AT) is a rare autosomal recessive disorder of childhood that results from defective DNA repair mechanisms. AT is a multisystemic choreoathetosis, oculocutaneous telangiectasias, frequent infections, increased sensitivity to ionizing radiation, and predisposition to malignancies.

Atelectasis is the collapse of lung volume.

Atopic dermatitis is a genetically determined eczematous eruption that is pruritic, symmetric,and associated with personal family history of allergic manifestations (atopy).

• Atrial fibrillation (AF) is a supraventricular tachyarrhythmia characterized by uncoordinated atrial activation with resultant deterioration in atrial mechanical function and often times irregular and rapid ventricular conduction The ventricular rate is dependent on the conduction properties of the atrioventricular node, which can be influenced by vagal/sympathetic tone, medications, or disease of the atrioventricular node.
• Multiple classification schemes have been used in the past to characterize AF. The current classification scheme (divided into three major types) used by the ACC/AHA guideline committee is as follows:
• � Paroxysmal atrial fibrillation: 2 or more episodes that terminate spontaneously within 7 days
• � Persistent atrial fibrillation: lasting >7 days.
• � Permanent atrial fibrillation: lasting >1 yr

Atrial flutter is characterized by an atrial macroreentrant circuit (typically in the right atrium) leading to regular atrial depolarizations, typically at a rate of 250 to 350 beats/min. There is typically 2:1 (or less) conduction through the atrioventricular node resulting in heart rates close to 150 beats/min. The atrial impulses may be conducted at a constant rate through the atrioventricular node resulting in a regular rhythm, or the atrial impulses may be conducted at a variable rate resulting in an irregular rhythm.

Atrial myxoma is a benign neoplasm of mesenchymal origin and is the most common primary tumor of the heart.

• Atrial septal defect (ASD) is an abnormal opening in the atrial septum that allows blood flow between the atria. It should be distinguished from patent foramen ovale, which is a persistent patency of the flaplike communication in which the septum primum covering the fossa ovalis overlaps the superior limbic band of the septum secundum. There are several forms:
• � Ostium primum: This type of ASD represents a deficiency of the endocardial cushion contribution to the atrial septum. It usually involves the atrioventricular valves.
• � Ostium secundum: This is the most common form; it represents a deficiency of the septum primum or a septum secundum, or both. Thisdefect most often occurs in the region of the fossa ovalis.
• � Sinus venosus defect: This defect is located at the junction of the right atrium and superior vena cava, and is not a "true ASD" as it does not involve the true atrial septum. In a sinus venusus defect, the wall separating the pulmonary veins and the right atrium is deficient, causing a left-to-right shunt. Most commonly this defect involves the right upper pulmonary vein, which is still connected to the left atrium, but the drainage is anomalous. Less commonly, the right lower pulmonary vein is involved.
• � Coronary sinus septal defect (unroofed coronary sinus): This defect results when the wall separating the coronary sinus from the left atrium is deficient, causing a right-to-left shunt. This is not a "true ASD" because it is not a defect in the atrial septum. This defect is often associated with a persistent left superior vena cava.

Attention deficit/hyperactivity disorder (ADHD) is a chronic disorder of attention and/or hyperactivity-impulsivity. Symptoms must be present before 7 yr of age, last at least 6 mo, and cause functional impairment in multiple settings.

Autism spectrum disorders (ASD) encompass a spectrum of developmental disorders characterized by marked social impairment. There is usually impairment in several additional domains, including the language and communication. Stereotypic behavior and sensory issues (i.e., hypersensitivity, hyposensitivity) also are prominent. Onset is typically before age 3 yr. and may be diagnosed as early as 15-18 mo of age. In rare cases, a child may be observed to develop normally to 18-24 mo and be diagnosed with autism at 30-36 mo.

Candidiasis is an inflammatory process involvingthe vulva or the vagina caused by superficialinvasion of epithelial cells by Candida species.

Carbon monoxide (CO) is a colorless, odorless,tasteless, nonirritating gas. When inhaled itproduces toxicity by causing cellular hypoxiaand damage.

Carcinoid syndrome is a symptom complexcharacterized by paroxysmal vasomotor disturbances,diarrhea, and bronchospasm. It iscaused by the action of amines and peptides(serotonin, bradykinin, histamine) produced bytumors arising from neuroendocrine cells.

Cardiac tamponade is a life-threatening conditionwhere an accumulation of fluid within the pericardialsac impairs filling of the ventricles duringdiastole and causes a decline in cardiac output.

Dilated cardiomyopathy describes a group of diseases involving the myocardium and characterized by myocardial dysfunction that is notprimarily the result of hypertension, coronarya therosclerosis, valvular dysfunction, or congenitalor other structural heart disease. As a result, the heart is enlarged and the ventriclesare dilated with impaired systolic function.

Cardiomyopathy describes a group of diseases that involve the myocardium and are characterized by myocardial dysfunction that is not primarilythe result of hypertension, coronary atherosclerosis,valvular dysfunction, congenital, or other structural heart disease. Hypertropic cardiomyopathy(HCM) is a primary myocardial disorder characterized by disorganized myocyte architecture and severe thickening (hypertrophy)of the left ventricular wall out of proportion to the resistance to ventricular contraction (afterload).The interventricular septum is the mostcommon site of enlargement, though hypertrophymay involve other focal regions or may be concentric. HCM may result in hemodynamically significant obstruction within the left ventricular outflow tract (LVOT) and/or impairment of thediastolic function of the left ventricle.

Cardiomyopathy, in general, describes a groupof diseases involving the myocardium and characterized by myocardial dysfunction that is notprimarily the result of hypertension, coronaryatherosclerosis, valvular dysfunction, congenital,or other structural heart disease. Restrictivecardiomyopathy is characterized by decreased ventricular compliance, with impaired ventricular filling (of either or both ventricles) and generally normal systolic function.

Syndrome characterized by transient systolicdysfunction and ballooning of the apical and/ormid segments of the left ventricle that mimics myocardial infarction (MI) but in the absence of obstructive (<70% for the three epicardial coronary vessels or <50% for left main) coronary artery disease that can explain the wall motion abnormality. Typically, but not always, it is preceded by severe illness or intense stress.

Light-headedness, dizziness, presyncope, orsyncope in a patient with carotid sinus hypersensitivityis defined as carotid sinus syndrome(CSS). Carotid sinus hypersensitivity is the exaggeratedresponse to carotid stimulation resultingin bradycardia, hypotension, or both.CSS is often considered a variant of neurocardiogenicsyncope.

Carotid stenosis is narrowing of the arterial lumen within the carotid artery that is typically a result of atherosclerosis.

Carpal tunnel syndrome is a compressive neuropathy of the median nerve as it passes under the transverse carpal ligament at the wrist. It is the most common entrapment neuropathy.

Cataracts are the clouding and opacification ofthe normally clear crystalline lens of the eye.The opacity may occur in the cortex, the nucleusof the lens, or the posterior subcapsular region,but it is usually in a combination of areas.

Cat-scratch disease (CSD) is a syndrome consisting of gradually enlarging regional lymphadenopathy occurring after contact with a feline.Atypical presentations are characterized by a variety of neurologic manifestations as well as granulomatous involvement of the eye, liver,spleen, and bone. The disease is usually self limiting,and recovery is complete; however,patients with atypical presentations, especially if immunocompromised, may suffer significant morbidity and mortality.

Cavernous sinus thrombosis (CST) is a late complication of facial or paranasal sinus infection,resulting in thrombosis of the cavernous sinus and inflammation of its surrounding anatomicstructures, including cranial nerves III, IV,V (ophthalmic and maxillary branch), and VI, and the internal carotid artery.

Celiac disease is a chronic autoimmune disease characterized by malabsorption and diarrhea precipitated by ingestion of food products containing gluten.

Cellulitis is a superficial inflammatory condition of the skin and underlying tissues characterized by erythema, warmth, and tenderness of the involved area.

Cerebral palsy (CP) is a group of disorders of the central nervous system characterized by aberrant control of movement or posture, present since early in life and not the result of a progressiveor degenerative disease.

Cerebral vasculitis refers to a group of heterogenous disorders characterized by pathologic inflammation and leukocytoclastic changes in the blood vessel walls.

Cervical cancer is penetration of the basement membrane and infiltration of the stroma of the uterine cervix by malignant cells.

Cervical disk syndromes refer to diseases of the cervical spine resulting from disk disorder, either herniation or degenerative change (spondylosis).When posterior osteophytes compress the anterior spinal cord, lower extremity symptoms may result, a condition called cervical spondylotic myelopathy.

Cervical dysplasia refers to atypical developmentof immature squamous epithelium thatdoes not penetrate the basement epithelial membrane. Characteristics include increased cellularity, nuclear abnormalities, and increased nuclear:cytoplasm ratio. A progressive polarized loss of squamous differentiation exists beginning adjacent to the basement membrane and progressing to the most advanced stage (severe dysplasia), which encompasses the complete squamous epithelial layer thickness. The revised 2001 Bethesda System terminology was used in a National Institutes of Health consensusconference, sponsored by the AmericanSociety for Colposcopy and Cervical Pathology(ASCCP) and its partner professional organizations in 2006. The conference updated therapeutic options for women based on studies such as the ASC-US (atypical squamous cells of undetermined significance)/LSIL (low-grade squamous intraepithelial lesions) Triage Study (ALTS) that appeared after revision of the Bethesda classification.

A cervical polyp is a growth protruding from the cervix or endocervical canal. Polyps that arise from the endocervical canal are called endocervical polyps. If they arise from the ectocervix,they are called cervical polyps.

Cervicitis is an infection of the cervix. It may result from direct infection of the cervix, or it maybe secondary to uterine or vaginal infection.

Chagas’ disease is an infection caused by the protozoan parasite Trypanosoma cruzi. This is a vector-borne disease transmitted by reduviid bugs from multiple wild and domesticated animal reservoirs. The disease is characterized by an acute nonspecific febrile illness that may be followed, after a variable latency period, by chronic cardiac, GI, and neurologic sequelae.

Chancroid is a sexually transmitted disease characterized by painful genital ulceration and inflammatory inguinal adenopathy.

Charcot-Marie-Tooth disease (CMT) is a heterogeneous group of noninflammatory inherited peripheral neuropathies characterized by chronic motor and sensory polyneuropathy. It is the most common inherited disorder of the peripheral nervous system (see also “Neuropathy, Hereditary”).

Charcot’s joint is a chronic, often devastating,progressive joint degeneration seen most commonlyin peripheral weight-bearing joints andvertebrae, which develops as a result of theloss of normal sensory innervation of the joint.It was described by Charcot as a result of tabesdorsalis.

Chemotherapy-induced nausea and vomiting(CINV) refers to adverse effects of drugs used to treat cancer. There are three recognized subtypes:acute-phase CINV, where nausea and vomiting begin minutes to hours after administrationof the drug(s); delayed-phase CINV,where symptoms can begin or return 24 hours or more after taking the medication(s); and anticipatory CINV, where nausea and vomiting begin before receiving treatment.

Genital infection with Chlamydia trachomatis may result in urethritis, epididymitis, cervicitis,and acute salpingitis, but often it is asymptomatici n women.In men, urethritis, mucopurulent discharge,dysuria, and urethral pruritus are noted.

Cholangitis refers to an inflammation and/or infection of the hepatic and common bile ducts associated with obstruction of the common bile duct.

Cholecystitis is acute or chronic inflammation of the gallbladder generally caused by gallstones(>95% of cases).

Cholelithiasis is the presence of stones in the gallbladder.

Cholera is an acute diarrheal illness caused byVibrio cholerae.

• Chronic fatigue syndrome (CFS) is characterizedby four or more of the following symptoms,present concurrently for at least 6 mo:
• • Impaired memory or concentration
• • Sore throat
• • Tender cervical or axillary lymph nodes
• • Muscle pain
• • Multijoint pain
• • New headaches
• • Unrefreshing sleep
• • Postexertion malaise

• Symmetric proximal and distal weakness with associated sensory loss along with reduced or absent reflexes for .
• >2 mo