China 
Africa 
- Sphingosine 1 phosphate
- Sphingosine kinase
- Sphingosine kinase 1
- Sphingosine-1-phosphate receptor
- Sphingosine-1-phosphate receptor modulator
- Sphygmograph
- Sphygmomanometer
- Sphygmomanometry
- Spider angiomas
- Spider bites
- Spider toxin
- Spider venom
- Spigelian hernia
- Spike and wave
- Spike protein
- Spike-timing-dependent plasticity
- Spillover
- Spin echo
- Spin label
- Spin probe
- Spin trapping
- Spin-lattice relaxation
- Spin-spin relaxation
- Spina bifida
- Spinal Cord Independence Measure
- Spinal and bulbar muscular atrophy
- Spinal anesthesia
- Spinal canal
- Spinal column
- Spinal cord
- Spinal cord compression
- Spinal cord disease
- Spinal cord injury
- Spinal cord injury research
- Spinal cord lesion
- Spinal cord stimulator
- Spinal disease
- Spinal dysraphism
- Spinal fractures
- Spinal fusion
- Spinal ganglion
- Spinal hematoma
- Spinal locomotion
- Spinal manipulation
- Spinal mobilization
- Spinal muscular atrophies
- Spinal needle
- Spinal nerve
- Spinal nerve root
- Spinal nerves
- Spinal posture
- Spinal precautions
- Spinal reflex
- Spinal root
- Spinal shock
- Spinal stenosis
- Spinal trigeminal nucleus
- Spinal tumor
- Spinal vein
- Spinalis
- Spinasterol
- Spindle apparatus
- Spindle cell carcinoma
- Spindle cell sarcoma
- Spindle cells
- Spindle checkpoint
- Spindle poison
- Spine
- Spine board
- Spine of scapula
- Spinel
- Spinocerebellar ataxia
- Spinocerebellar ataxia type 6
- Spinocerebellar tract
- Spinoglenoid notch
- Spinomesencephalic tract
- Spinoreticular tract
- Spinosad
- Spinothalamic tract
- Spinous cell
- Spinous process
- Spinraza
- Spintronics
- Spiperone
- Spiracle
- Spiracles
- Spiradenoma
- Spiral artery
- Spiral bacteria
- Spiral fracture
- Spiral ganglion
- Spiral lamina
- Spiral ligament
- Spiral limbus
- Spiritual crisis
- Spiritual distress
- Spiritual healing
- Spiro compounds
- Spirochaeta
- Spirochaetaceae
- Spirochaetes
- Spirochetes
- Spiroindolone
- Spirolactone
- Spirometer
- Spirometry
- Spironolactone
- Spiropyran
- Spirulina
- Spirurida
- Spitting
- Spitz nevi
- Splanchnic
- Splanchnic nerve
- Splanchnic nerves
- Spleen
- Splenda
- Splenectomy
- Splenic artery
- Splenic flexure
- Splenic infarction
- Splenic injury
- Splenic marginal zone lymphoma
- Splenic sequestration crisis
- Splenic vein
- Splenium
- Splenius
- Splenius capitis
- Splenius capitis muscle
- Splenius muscle
- Splenocytes
- Splenomegaly
- Splenosis
- Splice site mutations
- Spliceosome
- Splicing
- Splicing factor
- Splint
- Splinter
- Splinter hemorrhages
- Split S2
- Split brain
- Split hand syndrome
- Splitting
- Spo11
- Spoilage
- Spondylarthritis
- Spondylitis
- Spondyloarthritis
- Spondyloarthropathy