Dictionary

audiogram A test of hearing at a range of sound frequencies.

atypical measles syndrome The modified expression of measles, as may occur in persons who were incompletely immunized against measles or who have compromised immune systems. Abbreviated AMS. AMS begins suddenly with high fever, headache, cough, and abdominal pain. A rash may appear 1 to 2 days later, often beginning on the limbs. Swelling (edema) of…

atypical Unusual, or not fitting a single diagnostic category.

attenuated virus A weakened, less vigorous virus. An attenuated virus may be used to make a vaccine that is capable of stimulating an immune response and creating immunity, but not of causing illness.

attenuate To weaken, or to make or become thin.

attention deficit hyperactivity disorder A disorder in which a person is unable to control behavior due to difficulty in processing neural stimuli, accompanied by an extremely high level of motor activity. Abbreviated ADHD. ADHD can affect children and adults, but it is easiest to perceive during schooling. A child with ADHD may be extremely distractible,…

attention deficit disorder See attention deficit hyperactivity disorder.

attention The act of attending to discrete stimuli in the environment. Learning is most efficient when a person is paying attention. Poor attention can be a key sign of behavior disorders in children, stress, or depression. See also attention deficit hyperactivity disorder.

attack, vasovagal See vasovagal reaction.

atropine psychosis A syndrome characterized by dry mouth, blurred vision, forgetfulness, and difficulty with urination that can be caused by the anticholinergic effects of some drugs, particularly antipsychotic medications. Treatment requires reducing or stopping the medication. See also anticholinergic.

atropine A drug, made from the belladonna plant, that is administered via injection, eye drops, or in oral form to relax muscles by inhibiting nerve responses.

atrophy A wasting away or diminution. Muscle atrophy is a decrease in muscle mass, often due to extended immobility.