- Rebound tenderness 789.6
- Recalcitrant patient V15.81
- Recanalization, thrombus - see Thrombosis
- Recession, receding
- Recklinghausen's disease (M9540/1) 237.71
- Recklinghausen-Applebaum disease (hemochromatosis) 275.0
- Reclus' disease (cystic) 610.1
- Recrudescent typhus (fever) 081.1
- Recruitment, auditory 388.44
- Rectalgia 569.42
- Rectitis 569.49
- Rectocele
- Rectosigmoid junction - see condition
- Rectosigmoiditis 569.89
- Rectourethral - see condition
- Rectovaginal - see condition
- Rectovesical - see condition
- Rectum, rectal - see condition
- Recurrent - see condition
- Red bugs 133.8
- Red cedar asthma 495.8
- Redness