| Abbreviation | Meaning |
|---|---|
| JCV | JC virus (named after the initials of an anonymous patient) |
| JEV | Japanese encephalitis virus |
| JIA | juvenile idiopathic arthritis |
| JMML | juvenile myelomonocytic leukemia |
| JMS | junior medical student, aka MS-3 |
| JODM | juvenile-onset diabetes mellitus |
| JP JPD JPDs | Jackson-Pratt drain |
| JRA | juvenile rheumatoid arthritis (now called juvenile idiopathic arthritis) |
| JVD | jugular venous distension |
| JVP | jugular venous pressure |