- Somnambulism 307.46
- Somnolence 780.09
- Sonne dysentery 004.3
- Soor 112.0
- Sore
- Sotos' syndrome (cerebral gigantism) 253.0
- Sounds
- South African cardiomyopathy syndrome 425.2
- South American
- Southeast Asian hemorrhagic fever 065.4
- Spacing, teeth, abnormal 524.30
- Spade-like hand (congenital) 754.89
- Spading nail 703.8
- Spanemia 285.9
- Spanish collar 605
- Sparganosis 123.5
- Spasm, spastic, spasticity (see also condition) 781.0
- Spasmodic - see condition
- Spasmophilia (see also Tetany) 781.7
- Spasmus nutans 307.3
- Spastic - see also Spasm
- Spasticity - see also Spasm
