| AAP | air at atmospheric pressure; American Academy of Pediatrics; American Academy of Pedodontics; Americ... |
|---|---|
| AAO | American Academy of Osteopathy; American Academy of Ophthalmology; American Academy of Optometry; Am... |
| AAN | AIDS-associated nephropathy; alpha-amino nitrogen; American Academy of Neurology; American Academy o... |
| APM | Academy of Parapsychology and Medicine; Academy of Physical Medicine; Academy of Psychosomatic Medic... |
| AAA | abdominal aortic aneurysm/aneurysmectomy; acne-associated arthritis; acquired aplastic anemia; acute... |