| NA | Avogadro constant or number; nalidixic acid; Narcotics Anonymous; network administrator; neuraminida... |
|---|---|
| NASEAN | National Association for State Enrolled Assistant Nurses |
| OTA | occupational therapy assistant; Office of Technology Assessment; ornithine transaminase; orthotoluid... |
| PA | panic attack; pantothenic acid; paralysis agitans; paranoia; passive aggressive; pathology; patient'... |
| PDA | patent ductus arteriosus; personal digital assistant; posterior descending artery; pulmonary disease... |