- Retin-A
- Retin-A-Micro
- retina
- retinoblastoma
- retinoic acid
- retinoid
- retinol
- retinyl palmitate
- retromolar trigone
- retroperitoneal
- retropubic prostatectomy
- retrospective
- retrospective cohort study
- retrospective study
- retroviral vector
- retrovirus
- reverse transcription
- ReVia
- Revlimid
- RevM10 gene
- Reye syndrome
- rF-TRICOM
- RFT5-dgA immunotoxin
- RG7204
- rhabdoid tumor
- rhabdomyosarcoma
- rheumatism
- rheumatoid arthritis
- Rheumatrex
- rhIL-11
- rhinoscope
- rhinoscopy
- rhizoxin
- rhubarb
- ribavirin
- riboflavin
- ribonucleic acid
- ribonucleotide reductase inhibitor
- ribosome
- Richter syndrome
- Richter transformation
- rickets
- ridaforolimus
- rifabutin
- rifampin
- Rilutek
- riluzole
- risedronate
- risk factor
- risk ratio