- Resorption
- Respiration
- Respiratory - see also condition
- Respiratory syncytial virus (RSV) 079.6
- Response
- Rest, rests
- Restless legs syndrome (RLS) 333.94
- Restlessness 799.29
- Restoration of organ continuity from previous sterilization (tuboplasty) (vasoplasty) V26.0
- Restriction of housing space V60.1
- Restzustand, schizophrenic (see also Schizophrenia) 295.6
- Retained - see Retention
- Retardation
- Retching - see Vomiting
- Retention, retained
- Reticulation, dust (occupational) 504
- Reticulocytosis NEC 790.99
- Reticuloendotheliosis
- Reticulohistiocytoma (giant cell) 277.89
- Reticulohistiocytosis, multicentric 272.8
- Reticulolymphosarcoma (diffuse) (M9613/3) 200.8
- Reticulosarcoma (M9640/3) 200.0