- Railroad neurosis 300.16
- Railway spine 300.16
- Raised - see Elevation
- Raiva 071
- Rake teeth, tooth 524.39
- Rales 786.7
- Ramifying renal pelvis 753.3
- Ramsay Hunt syndrome (herpetic geniculate ganglionitis) 053.11
- Ranke's primary infiltration (see also Tuberculosis) 010.0
- Ranula 527.6
- Rape
- Rapid
- Rarefaction, bone 733.99
- Rash 782.1
- Rasmussen's aneurysm (see also Tuberculosis) 011.2
- Rat-bite fever 026.9
- Rathke's pouch tumor (M9350/1) 237.0
- Raymond (-Céstan) syndrome 433.8
- Raynaud's
- RDS 769
- Reaction
- Reactive depression (see also Reaction, depressive) 300.4