Astraphobia: An abnormal and persistent fear of thunderstorms. Sufferers experience anxiety even when they realize the risk of harm is very small. Consequently, when indoors they might seek shelter under a bed, in a closet or in a basement. They generally keep a watchful eye on the sky and remain alert for reports of electrical storms.
“Astraphobia” is derived from the Greek “aster” (star) and “phobos” (fear).
Related term: Brontophobia: Fear of thunder.
Astrocytoma: A tumor that begins in the brain or spinal cord in small, star-shaped cells called astrocytes. The location of the tumor depends on the age of the person. In adults, astrocytomas most often arise in the cerebrum, whereas in children, they may arise in the brain stem, cerebrum, and cerebellum.
Asymptomatic: Without symptoms. For example, an asymptomatic infection is an infection with no symptoms.
- Asymptomatic infection
Asymptomatic infection: An infection without symptoms. Also known as inapparent or subclinical infection.
Asystole: A dire form of cardiac arrest in which the heart stops beating and there is no electrical activity in the heart. As a result, the heart is at a total standstill.
Asbestosis: A condition featuring scarring of the lungs caused by inhaled asbestos fibers. Asbestosis is irreversible. Asbestosis can also lead to lung cancer or to mesothelioma, a cancer of the lining on the surface of the lung.