| OBS(?) | Organic Brain Syndrome |
|---|---|
| Obst | obstetrics, obstetrician |
| obst, obstr | obstruction, obstructed |
| OC | 1) Osteo-Calcin 2) Oral Contraceptive |
| OC | obstetrical conjugate; occlusocervical; office call; on call; only child; optic chiasma; oral contraceptive; order communication [system]; original claim; organ culture; outer canthal [distance]; ovarian cancer; oxygen consumed |
| OC&P | ova, cysts, and parasites |
| OCA | Oculo-Cutaneous Albinism |
| OCA | oculocutaneous albinism; olivopontocerebellar atrophy; oral contraceptive agent |
| OCa | ovarian carcinoma |
| OCAA | Ovarian Cystadenocarcinoma Associated Antigen; Serous Mucinous Ovarian Tumor에만 나타남 |