- Rabies - 26 Studies
- Radial Neuropathy - 2 Studies
- Radiation Injuries - 25 Studies
- Radiation Pneumonitis - 19 Studies
- Radiculopathy - 25 Studies
- Radiodermatitis - 25 Studies
- Radius Fractures - 25 Studies
- Rare Diseases - 25 Studies
- Rasmussen Encephalitis - 2 Studies
- Raynaud Disease - 25 Studies
- Reactive Arthritis - 7 Studies
- Recessive Dystrophic Epidermolysis Bullosa - 16 Studies
- Rectal Fistula - 25 Studies
- Rectal Neoplasms - 27 Studies
- Rectal Prolapse - 25 Studies
- Rectocele - 2 Studies
- Rectovaginal Fistula - 3 Studies
- Recurrent Respiratory Papillomatosis - 18 Studies
- Red-Cell Aplasia, Pure - 25 Studies
- Refeeding Syndrome - 8 Studies
- Reflex Sympathetic Dystrophy - 25 Studies
- Reflex, Abnormal - 7 Studies
- Refractive Errors - 29 Studies
- Refsum Disease - 5 Studies
- Refsum Disease, Infantile - 4 Studies
- Refsum Disease, Infantile Form - 4 Studies
- Relapsing Fever - 2 Studies
- Relapsing Polychondritis - 6 Studies
- REM Sleep Behavior Disorder - 22 Studies
- Remission, Spontaneous - 2 Studies
- Renal Agenesis - 2 Studies
- Renal Artery Obstruction - 25 Studies
- Renal Colic - 27 Studies
- Renal Medullary Carcinoma - 4 Studies
- Renal Oncocytoma - 2 Studies
- Renal Osteodystrophy - 20 Studies
- Renal Tubular Acidosis - 5 Studies
- Renal Tubular Transport, Inborn Errors - 20 Studies
- Reperfusion Injury - 20 Studies
- Respiratory Aspiration of Gastric Contents - 8 Studies
- Respiratory Distress Syndrome, Adult - 20 Studies
- Respiratory Distress Syndrome, Infant - 20 Studies
- Respiratory Distress Syndrome, Newborn - 26 Studies
- Respiratory Insufficiency - 23 Studies
- Respiratory Paralysis - 12 Studies
- Respiratory Sounds - 20 Studies
- Respiratory Syncytial Virus Infections - 28 Studies
- Respiratory System Abnormalities - 20 Studies
- Restless Legs Syndrome - 21 Studies
- Restless Legs Syndrome, Susceptibility To, 1 - 2 Studies
- Restless Legs Syndrome, Susceptibility To, 6 - 2 Studies
- Reticular Dysgenesis - 3 Studies
- Retinal Artery Occlusion - 17 Studies
- Retinal Detachment - 21 Studies
- Retinal Drusen - 3 Studies
- Retinal Dystrophies - 21 Studies
- Retinal Hemorrhage - 5 Studies
- Retinal Neoplasms - 20 Studies
- Retinal Neovascularization - 18 Studies
- Retinal Perforations - 20 Studies
- Retinal Telangiectasis - 2 Studies
- Retinal Vasculitis - 11 Studies
- Retinal Vein Occlusion - 20 Studies
- Retinitis - 19 Studies
- Retinitis Pigmentosa - 24 Studies
- Retinitis Pigmentosa-deafness Syndrome - 12 Studies
- Retinoblastoma - 20 Studies
- Retinopathy of Prematurity - 22 Studies
- Retinoschisis - 13 Studies
- Retrognathia - 6 Studies
- Retroperitoneal Fibrosis - 7 Studies
- Retroperitoneal Liposarcoma - 2 Studies
- Retroperitoneal Neoplasms - 4 Studies
- Rett Syndrome - 27 Studies
- Reversible Cerebral Vasoconstriction Syndrome - 3 Studies
- Rhabdoid Tumor - 21 Studies
- Rhabdomyolysis - 20 Studies
- Rhabdomyosarcoma - 21 Studies
- Rhabdomyosarcoma Alveolar - 11 Studies
- Rhabdomyosarcoma Embryonal - 11 Studies
- Rhabdomyosarcoma, Alveolar - 10 Studies
- Rhabdomyosarcoma, Embryonal - 20 Studies
- Rheumatic Fever - 20 Studies
- Rheumatic Heart Disease - 21 Studies
- Rhinitis - 20 Studies
- Rhinitis, Allergic - 23 Studies
- Rhinitis, Allergic, Perennial - 20 Studies
- Rhinitis, Allergic, Seasonal - 20 Studies
- Rhinitis, Atrophic - 3 Studies
- Rhinitis, Vasomotor - 9 Studies
- Rib Fractures - 27 Studies
- Richter Syndrome - 20 Studies
- Rickets - 21 Studies
- Rickets, Hypophosphatemic - 20 Studies
- Rickettsia Infections - 11 Studies
- Rift Valley Fever - 4 Studies
- ROHHAD - 3 Studies
- Root Caries - 4 Studies
- Root Resorption - 7 Studies
- Rosacea - 20 Studies
- Rosai-Dorfman Disease - 2 Studies
- Rotavirus Infections - 20 Studies
- Rothmund-Thomson Syndrome - 2 Studies
- Roussy Levy Syndrome - 20 Studies
- Rubella - 19 Studies
- Rumination Disorder - 20 Studies
- Rupture - 20 Studies
- Rupture, Spontaneous - 7 Studies
- Russell-Silver Syndrome - 3 Studies