- Subsiding appendicitis 542
- Substernal thyroid (see also Goiter) 240.9
- Substitution disorder 300.11
- Subtentorial - see condition
- Subtertian
- Subthyroidism (acquired) (see also Hypothyroidism) 244.9
- Succenturiata placenta - see Placenta, abnormal
- Succussion sounds, chest 786.7
- Sucking thumb, child 307.9
- Sudamen 705.1
- Sudamina 705.1
- Sudanese kala-azar 085.0
- Sudden
- Sudeck's atrophy, disease, or syndrome 733.7
- SUDS (Sudden unexplained death) 798.2
- Suffocation (see also Asphyxia) 799.01
- Sugar
- Suicide, suicidal (attempted)
- Suipestifer infection (see also Infection, Salmonella) 003.9
- Sulfatidosis 330.0
- Sulfhemoglobinemia, sulphemoglobinemia (acquired) (congenital) 289.7
- Sumatran mite fever 081.2
