| Abbreviation | Definition |
|---|---|
| OMFU | oral and maxillofacial unit |
| OMNIXX | Organising Medical Networked Information |
| OMP | olfactory marker protein |
| OMP | omeprazole |
| OMP | Ophthalmic Medical Practitioner |
| ONS | optical nerve sheath |
| ONS | optical nerves |
| ONSformatXX | Office for National Statistics format |
| OOH | out of hospital |
| OOHH | Out Of Hours Healthcare |
| OOP | out of programme |
| OOPC | out of programme for career break |
| OOPE | out of programme for experience |
| OOPR | out of programme for research |
| OOPT | out of programme for clinical teaching |
| OP | occipitoparietal |
| OP | oesophagopharyngeal |
| OP | opium |
| OP | opponens pollicis |
| OP | osteopaenia |