S health terms
- S1
- S2
- S3
- S4
- Saddle nose deformity
- Salter-Harris fracture
- Sarcoidosis
- Sarcoma
- Sarcomere
- Sarcoptes scabiei
- Sarin
- Scaffolding protein
- Schamroth's sign
- Schistosomiasis
- Schwann cell
- Seborrhea
- Second messengers
- Sellick's maneuver
- Sensitivity
- Serial dilution
- Serotonin
- Serum sickness
- Sesamoid bone
- Short-term memory
- Shoulder dystocia
- Simple pulmonary eosinophilia
- Sincalide
- Smallpox
- Somatostatin
- Specificity
- Spectrin
- Spina bifida
- Splenic sequestration crisis
- Splinter hemorrhages
- SSRI
- Stevens-Johnson syndrome
- Stria terminalis
- Striate body
- Stridor
- Stroma
- Strontium
- Strontium ranelate
- Stricnine
- Sturge-Weber disease
- Subclavian
- Subclavian steal syndrome
- Sulfonamide
- Sulfonylurease
- Sweet syndrome
- Syndactyly
- Syringomyelia
- Systole
- Systolic gradient
- Systolic murmur
- Systolic thrill
