| Abbreviation | Definition |
|---|---|
| PI | poison ivy |
| PI | post implantation |
| PI | post infection |
| PI | post inoculation |
| PI | post irradiation |
| PI | post ischaemic |
| PI | primary infection |
| PI | prognostic index |
| PI | proliferation index |
| PI | pulmonary index |
| PI | pulmonary infarction |
| PI | pulse inversion |
| PIAG | Public Involvement Action Group |
| PIB | partial ileal byposs |
| PIB | Permanent Injury Benefit |
| PIB | polyhedral inclusion body |
| PICS | Prescribing Information and Communications System (PICS) |
| PICSXX | Pacing in Cardiomyopathy Study |
| PICU | paediatric intensive care unit |
| PICU | psychiatric intensive care unit |