- Retroplacental - see condition
- Retroposition - see Retroversion
- Retroprosthetic membrane 996.51
- Retrosternal thyroid (congenital) 759.2
- Retroversion, retroverted
- Retrusion, premaxilla (developmental) 524.04
- Rett's syndrome 330.8
- Reverse, reversed
- Reye's syndrome 331.81
- Reye-Sheehan syndrome (postpartum pituitary necrosis) 253.2
- Rh antigen (C) (c) (D) (E) (e) (factor)
- Rhabdomyolysis (idiopathic) 728.88
- Rhabdomyoma (M8900/0) - see also Neoplasm, connective tissue, benign
- Rhabdomyosarcoma (M8900/3) - see also Neoplasm connective tissue, malignant
- Rhabdosarcoma (M8900/3) - see Rhabdomyosarcoma
- Rhesus (factor) (Rh) incompatibility - see Rh, incompatibility
- Rheumaticosis - see Rheumatism
- Rheumatism, rheumatic (acute NEC) 729.0
- Rheumatoid - see also condition
- Rhinitis (atrophic) (catarrhal) (chronic) (croupous) (fibrinous) (hyperplastic) (hypertrophic) (membranous) (purulent) (suppurative) (ulcerative) 472.0
- Rhinoantritis (chronic) 473.0
- Rhinodacryolith 375.57
