activities of daily living Things that a person normally does during a day, including self-care (eating, bathing, dressing, grooming), work, homemaking, and leisure. The ability or inability to perform these activities can be used as a practical measure of ability or disability, and it may be used by insurers and HMOs as a rationale for…
active immunity Immunity produced by the body in response to stimulation by a disease-causing organism or other agent.
active euthanasia The active acceleration of a terminally ill patient’s death by use of drugs or other means. Currently, active euthanasia is openly practiced in the Netherlands and in the US state of Oregon. The patient’s request to the physician must be voluntary, explicit, and carefully considered, and it must be made repeatedly. Moreover, the…
activated charcoal Charcoal that has been heated to increase its ability to absorb molecules. Activated charcoal is used to help relieve intestinal gas. It is also used to filter and purify liquids, to absorb poisons (as in gas mask filters), and in emergency situations to neutralize swallowed poisons.
actinic keratosis Rough, scaly patches of skin that are considered precancerous and are due to sun exposure. Prevention is to cut sun exposure and wear sunscreen. Treatments include performing cryosurgery (freezing with liquid nitrogen), cutting the keratoses away, burning them, putting 5-fluorouracil on them, and using photodynamic therapy (injecting into the bloodstream a chemical that…
actinic Referring to the ultraviolet (UV) rays from sunlight and UV lamps. Sunburn is an actinic burn. An actinic keratosis is a skin lesion that is the consequence of chronic sun exposure.
ACS American College of Surgeons, a professional organization that administers standards of practice for surgeons. Those who meet the group’s standards can call themselves Fellows of the ACS.
acrosyndactyly A condition in which a person has fused or webbed fingers or toes. Acrosyndactyly can be partial or complete, and it can usually be corrected via surgery. It is associated with several birth defect syndromes. See also Apert syndrome.
acromioclavicular joint A gliding joint located between the acromion (a projection of the scapula that forms the point of the shoulder) and the clavicle (the collar bone). It is served and supported by the capsular, superior, and inferior acromioclavicular ligaments; the articular disk; and the coracoclavicular (trapezoid and conoid) ligaments. Abbreviated AC joint.
acromegaly See gigantism, pituitary.
acrodermatitis enteropathica A progressive, hereditary disease of children, characterized by the simultaneous occurrence of skin inflammation (dermatitis) and diarrhea. The skin on the cheeks, elbows, and knees is inflamed, as is tissue about the mouth and anus. There is also balding of the scalp, eyebrows, and lashes; delayed wound healing; and recurrent bacterial and fungal…
acrocyanosis Blueness of the hands and feet, usually due to inadequate circulation.