| APB | abductor pollicis brevis; atrial premature beat |
|---|---|
| APC | acetylsalicylic acid, phenacetin, and caffeine; activated protein C; adenoidal-pharyngeal-conjunctiv... |
| APD | action potential duration; acute polycystic disease; advanced physical diagnosis; anteroposterior di... |
| AR | absolute risk; accounts receivable; achievement ratio; actinic reticuloid [syndrome]; active resista... |
| ASD | aldosterone secretion defect; Alzheimer senile dementia; antisiphon device; arthritis syphilitica de... |