- Rickettsial disease 083.9
- Rickettsialpox 083.2
- Rickettsiosis NEC 083.9
- Ricord's chancre 091.0
- Riddoch's syndrome (visual disorientation) 368.16
- Rider's
- Ridge, alveolus - see also condition
- Ridged ear 744.29
- Riedel's
- Rieger's anomaly or syndrome (mesodermal dysgenesis, anterior ocular segment) 743.44
- Riehl's melanosis 709.09
- Rietti-Greppi-Micheli anemia or syndrome 282.46
- Rieux's hernia - see Hernia, Rieux's
- Rift Valley fever 066.3
- Riga's disease (cachectic aphthae) 529.0
- Riga-Fede disease (cachectic aphthae) 529.0
- Riggs' disease (compound periodontitis) 523.40
- Right middle lobe syndrome 518.0
- Rigid, rigidity - see also condition
- Rigors 780.99
- Riley-Day syndrome (familial dysautonomia) 742.8
- RIND (reversible ischemic neurological deficit) 434.91
