China 
Africa 
- Schimmelpenning syndrome
- Schirmer test
- Schirmer's test
- Schisandra
- Schisandra Chinensis
- Schistocytes
- Schistosoma
- Schistosoma haematobium
- Schistosoma japonicum
- Schistosoma mansoni
- Schistosomatidae
- Schistosomiasis
- Schistosomiasis vaccine
- Schizencephaly
- Schizoaffective disorder
- Schizoid personality disorder
- Schizonepeta
- Schizont
- Schizophrenia
- Schizophreniform disorder
- Schizophyllan
- Schizosaccharomyces
- Schizosaccharomyces pombe
- Schizotypal personality disorder
- Schizotypy
- Schiøtz tonometer
- Schlemm's canal
- Schlieren
- Schmorl's nodes
- Schneiderian membrane
- Schnitzler syndrome
- Schober's test
- Schofield equation
- School psychology
- School refusal
- School social work
- School social worker
- Schwalbe's line
- Schwann cells
- Schwannoma
- Schwannomatosis
- Schwartz-Jampel syndrome
- Sciatic nerve
- Sciatic nerve injury
- Sciatic neuropathy
- Sciatica
- Scientist-Practitioner Model
- Scimitar syndrome
- Scintigraphy
- Scintillating scotoma
- Scintillation
- Scintillation counters
- Scintillation counting
- Scintillation detector
- Scintillators
- Scissile bond
- Scissor gait
- Sclareol
- Sclera
- Scleral buckle
- Scleral lenses
- Scleral spur
- Scleredema
- Sclerema neonatorum
- Sclerenchyma
- Sclerite
- Scleritis
- Sclerocarya birrea
- Sclerocornea
- Sclerodactyly
- Scleroderma
- Sclerosing agents
- Sclerosing epithelioid fibrosarcoma
- Sclerosis
- Sclerosteosis
- Sclerostin
- Sclerotherapy
- Sclerotic fibroma
- Sclerotic ring
- Sclerotin
- Sclerotiorin
- Sclerotome
- Scolex
- Scoliometer
- Scoliosis
- Scoop stretcher
- Scopolamine
- Scorpion sting
- Scorpion toxin
- Scotomas
- Scotopic vision
- Scott syndrome
- Scramblase
- Scrambler therapy
- Scrapie
- Scree plot
- Screen readers
- Screen time
- Screening
- Screening cultures
- Scrofula
- Scrofuloderma
- Scrotal
- Scrotal ultrasonography
- Scrotal ultrasound
- Scrotoplasty
- Scrub typhus
- Scrupulosity
- Sculptra
- Scurvy
- Scutellarein
- Scutellaria
- Scutellaria baicalensis
- Scutellaria barbata
- Scutellaria lateriflora
- Scutellarin
- Scyllo-Inositol
- Scytonemin
- SeHCAT
- Sea buckthorn oil
- Sea cucumber
- Sea salt
- Sea urchin
- Sea-blue histiocytosis
- Seadornavirus
- Seasonal adjustment
- Seasonal affective disorder
- Seasonal pattern
- Seasonality
- Seat belts
- Sebaceoma
- Sebaceous adenoma
- Sebaceous carcinoma
- Sebaceous cysts
- Sebaceous gland
- Sebaceous gland hyperplasia
- Sebaceous glands
- Sebaceous hyperplasia
- Sebacic acid
- Seborrhea
- Seborrheic dermatitis
- Seborrheic keratosis
- Sebum
- Sec61
- SecA
- Secale cereale
- Secalin
- Seckel syndrome
- Seclusion
- Secnidazole