| RTI | respiratory tract infection; reverse transcriptase inhibition |
|---|---|
| RURTI | recurrent upper respiratory tract infection |
| RV | random variable; rat virus; Rauscher virus; rectovaginal; reinforcement value; renal vein; residual ... |
| RW | radiological warfare; ragweed; respiratory work; Romano-Ward [syndrome]; round window |
| SRDS | severe respiratory distress syndrome |