- Suipestifer infection (see also Infection, Salmonella) 003.9
- Sulfatidosis 330.0
- Sulfhemoglobinemia, sulphemoglobinemia (acquired) (congenital) 289.7
- Sumatran mite fever 081.2
- Summer - see condition
- Sunburn 692.71
- SUNCT (short lasting unilateral neuralgiform headache with conjunctival injection and tearing) 339.05
- Sunken
- Sunstroke 992.0
- Superfecundation 651.9
- Superfetation 651.9
- Superinvolution uterus 621.8
- Supernumerary (congenital)
- Supervision (of)
- Supplemental teeth 520.1
- Suppression
- Suppuration, suppurative - see also condition
- Supraeruption, teeth 524.34
- Supraglottitis 464.50
- Suprapubic drainage 596.8
- Suprarenal (gland) - see condition
- Suprascapular nerve - see condition