| Reference Books, Medical |
| Reference Standards |
| Reference Values |
| Referral and Consultation |
| Reflex |
| Reflex Sympathetic Dystrophy |
| Reflex, Abdominal |
| Reflex, Abnormal |
| Reflex, Acoustic |
| Reflex, Babinski |
| Reflex, Oculocardiac |
| Reflex, Pupillary |
| Reflex, Stretch |
| Reflex, Vestibulo-Ocular |
| Reflexotherapy |
| Refraction, Ocular |
| Refractive Errors |
| Refractometry |
| Refractory Period, Psychological |
| Refsum Disease |
| Refugees |
| Refusal to Participate |
| Refusal to Treat |
| Refuse Disposal |
| Regenerative Medicine |
| Regional Blood Flow |
| Regional Health Planning |
| Regional Medical Programs |
| Registries |
| Regression (Psychology) |
| Regression Analysis |
| Regulatory Elements, Transcriptional |
| Regulatory Sequences, Nucleic Acid |
| Regulatory Sequences, Ribonucleic Acid |
| Regulon |
| Rehabilitation |
| Rehabilitation Centers |
| Rehabilitation Nursing |
| Rehabilitation of Hearing Impaired |
| Rehabilitation of Speech and Language Disorders |
| Rehabilitation, Vocational |
| Rehmannia |
| Rehydration Solutions |
| Reimbursement Mechanisms |
| Reimbursement, Disproportionate Share |
| Reimbursement, Incentive |
| Reindeer |
| Reinforcement (Psychology) |
| Reinforcement Schedule |
| Reinforcement, Social |
| Reinforcement, Verbal |
| Reishi |
| Reiter Disease |
| Rejection (Psychology) |
| Rejuvenation |
| Relapsing Fever |
| Relative Biological Effectiveness |
| Relative Value Scales |
| Relaxation |
| Relaxation Techniques |
| Relaxin |
| Relief Work |
| Religion |
| Religion and Medicine |
| Religion and Psychology |
| Religious Philosophies |
| REM Sleep Behavior Disorder |
| REM Sleep Parasomnias |
| Remedial Teaching |
| Reminder Systems |
| Remission Induction |
| Remission, Spontaneous |
| Remote Consultation |
| Remoxipride |
| Renal Agents |
| Renal Artery |
| Renal Artery Obstruction |
| Renal Blood Flow, Effective |
| Renal Circulation |
| Renal Dialysis |
| Renal Insufficiency |
| Renal Insufficiency, Acute |
| Renal Insufficiency, Chronic |
| Renal Osteodystrophy |
| Renal Plasma Flow |
| Renal Plasma Flow, Effective |
| Renal Replacement Therapy |
| Renal Tubular Transport, Inborn Errors |
| Renal Veins |
| Renilla |