Dictionary

aneurysm, saccular An aneurysm that resembles a small sack. A berry aneurysm is typically saccular.

aneurysm, thoracic An aneurysm of the largest artery in the body, the aorta, involving that vessel in its course within the thorax (chest). Because of the volume of blood flowing under relatively high pressure within the aorta, a ruptured aneurysm of the aorta is a catastrophe. See also aneurysm, abdominal aortic; aneurysm, aortic.

aneurysm, venous A localized widening of a vein.

anger An emotional state that may range in intensity from mild irritation to intense fury and rage. Anger has physical effects, including raising the heart rate and blood pressure, as well as the levels of adrenaline.

angiitis Inflammation of the walls of small blood vessels. Also known as vasculitis.

angiitis, allergic granulomatous See ChurgStrauss syndrome.

angina Chest pain due to an inadequate supply of oxygen to the heart muscle. The pain is typically severe and crushing, and it is characterized by a feeling of pressure and suffocation just behind the breastbone. Angina can accompany or be a precursor of a heart attack.

angina, Prinzmetal Chest pain due to a coronary artery spasm, a sudden constriction of one of the vessels that supply the heart muscle with blood that is rich in oxygen. This spasm deprives the heart muscle of blood and oxygen. Treatments include beta-blocker medications and nitroglycerin to open up the coronary arteries. Also known as…

androsterone A male sex hormone that is found in the blood and urine of men and women. It is seven times weaker than testosterone.

anemia The condition of having a lower-thannormal number of red blood cells or quantity of hemoglobin. Anemia diminishes the capacity of the blood to carry oxygen. Patients with anemia may feel tired, fatigue easily, appear pale, develop palpitations, and become short of breath. Children with chronic anemia are prone to infections and learning problems. The…

anemia, Addisonian See anemia, pernicious.

anemia, aplastic Anemia due to failure of the bone marrow to produce red and white blood cells as well as platelets. Aplastic anemia frequently occurs without a known cause. Known causes include exposure to chemicals (for example, benzene, toluene in glues, insecticides, solvents), drugs (for example, chemotherapy drugs, gold, seizure medications, antibiotics), viruses (for instance,…