- Smith-Lemli-Opitz syndrome (cerebrohepatorenal syndrome) 759.89
- Smith-Magenis syndrome 758.33
- Smith-Strang disease (oasthouse urine) 270.2
- Smokers'
- Smoking complicating pregnancy, childbirth, or the puerperium 649.0
- Smothering spells 786.09
- Snaggle teeth, tooth 524.39
- Snapping
- Sneddon-Wilkinson disease or syndrome (subcorneal pustular dermatosis) 694.1
- Sneezing 784.99
- Sniffing
- Snoring 786.09
- Snow blindness 370.24
- Snuffles (nonsyphilitic) 460
- Social migrant V60.0
- Sodoku 026.0
- Soemmering's ring 366.51
- Soft - see also condition
- Softening
- Soiling, fecal 787.62
- Solar fever 061
- Soldier's