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Description Acute cholecystitis is the most common complication of cholelithiasis. In fact, ≥ 95% of patients with acute cholecystitis have cholelithiasis. When a stone becomes impacted in the cystic duct and persistently obstructs it, acute inflammation results. Bile stasis triggers release of inflammatory enzymes (eg, phospholipase A, which converts lecithin …

Definition Anterior cruciate ligament injury passes in front of another ligament, the posterior cruciate ligament (PCL). The cruciate ligaments get their name from the fact they form a cross within the knee as they run in different directions from the thigh to the shin bone. Along with the other ligaments …

Overview Atrioventricular canal defect (AVCD) or atrioventricular septal defect (AVSD) is a combination of heart problems resulting in a defect in the center of the heart. The condition occurs when there’s a hole between the heart’s chambers and problems with the valves that regulate blood flow in the heart. Sometimes …

Overview of acute lymphocytic leukemia (ALL) Acute lymphocytic leukemia (ALL) is a type of cancer of the blood and bone marrow — the spongy tissue inside bones where blood cells are made. The word “acute” in acute lymphocytic leukemia comes from the fact that the disease progresses rapidly and creates …

Description Anaplasmosis is a disease caused by the bacterium Anaplasma phagocytophilum. These bacteria are spread to people by tick bites primarily from the blacklegged tick (Ixodes scapularis) and the western blacklegged tick (Ixodes pacificus). People with anaplasmosis will often have fever, headache, chills, and muscle aches. Doxycycline is the drug …

Definition Adrenomyeloneuropathy (AMN) is an inherited condition that affects the spinal cord. It is a form of X-linked adrenoleukodystrophy. On average, people with AMN begin to develop features in the late twenties. Signs and symptoms may include progressive stiffness and weakness of the legs; ataxia; speech difficulties; adrenal insufficiency; sexual …

Overview Amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig’s disease, is a progressive degeneration of nerve cells that control muscle movements. The disease, the most common motor neuron disease among adults, became known as Lou Gehrig’s disease after the New York Yankee’s Hall of Fame first baseman. Gehrig’s career …

Definition Anosmia is the full loss of smell. Anosmia can be a temporary or permanent condition. You can partially or completely lose your sense of smell when the mucus membranes in your nose are irritated or obstructed such as when you have a severe cold or a sinus infection, for …