- Respiratory Acidosis
- Respiratory Alkalosis
- Respiratory Distress Syndrome
- Respiratory Failure
- Respiratory Syncytial Virus Infection
- Restless Legs Syndrome
- Restrictive Cardiomyopathy
- Reticulocyte Count
- Retinal Artery Occlusion
- Retinal Detachment
- Retinal Vein Occlusion
- Retinitis Pigmentosa
- Retinoblastoma
- Retinopathies
- Retrograde Cystography
- Retrograde Ureteropyelography
- Retrograde Urethrography
- Reye's Syndrome
- Rheumatic Fever
- Rheumatoid Arthritis
- Rhinitis
- Rhinoplasty
- Riboflavin Deficiency
- Rickettsialpox
- Ringworm
- Rocky Mountain Spotted Fever
- Rolfing
- Root Canal Treatment
- Rosacea
- Roseola
