| NS | natural science; Neosporin; nephrosclerosis; nephrotic syndrome; nervous system; neurological surger... |
|---|---|
| OBGS | obstetrical and gynecological surgery |
| OH | hydroxycorticosteroid; obstructive hypopnea; occipital horn; occupational health; occupational histo... |
| OHS | obesity hypoventilation syndrome; occipital Horn syndrome; occupational health service; ocular histo... |
| OM&S | osteopathic medicine and surgery |