China 
Africa 
- Two-alternative forced choice
- Two-component regulatory system
- Two-dimensional chromatography
- Two-hit hypothesis
- Two-hybrid system
- Two-point discrimination
- Two-pore channels
- Tylenol
- Tymovirales
- Tymoviridae
- Tympanic cavity
- Tympanic membrane
- Tympanic nerve
- Tympanocentesis
- Tympanometry
- Tympanoplasty
- Tympanosclerosis
- Tympanum
- Tympany
- Tyndall effect
- Tyndallization
- Type 1
- Type 1 diabetes
- Type 1 diabetes mellitus
- Type 2 diabetes
- Type 2 inflammation
- Type 3 innate lymphoid cells
- Type 3c diabetes
- Type D personality
- Type I
- Type I collagen
- Type I hypersensitivity
- Type I interferon
- Type I keratin
- Type II
- Type II collagen
- Type II hypersensitivity
- Type III
- Type III error
- Type III hypersensitivity
- Type III secretion system
- Type IV
- Type IV collagen
- Type IV hypersensitivity
- Type IV secretion system
- Type V collagen
- Type VII secretion system
- Type-V collagen
- Typhidot
- Typhlitis
- Typhoid fever
- Typhus
- Typical antipsychotics
- Typology
- Tyramine
- Tyrocidine
- Tyrode's solution
- Tyrosinase
- Tyrosine
- Tyrosine aminotransferase
- Tyrosine ammonia lyase
- Tyrosine ammonia-lyase
- Tyrosine decarboxylase
- Tyrosine hydroxylase
- Tyrosine hydroxylase deficiency
- Tyrosine kinase 2
- Tyrosine kinase inhibitors
- Tyrosine kinase receptors
- Tyrosine kinases
- Tyrosine phosphorylation
- Tyrosine sulfation
- Tyrosinemia
- Tyrosinemia type I
- Tyrosinemia type II
- Tyrosol
- Tyrothricin
- Tzanck smear
- Tzanck test
- U wave
- U-47700
- U-50488
- U-87 MG
- U0126
- U937
- UAV
- UCHL1
- UCLA Loneliness Scale
- UCP1
- UCP2
- UDI
- UDP-glucose pyrophosphorylase
- UDP-glucuronosyltransferase
- UGT1A1
- UGT2B7
- ULV
- UMLS
- UNC13A
- UPGMA
- UQCRB
- UQCRC2
- UR-144
- URA3
- URB597
- USAN
- USDA National Nutrient Database
- USP18
- UTS2R
- UTX
- Ubidecarenone
- Ubiquinol
- Ubiquinone
- Ubiquitin
- Ubiquitin carboxy-terminal hydrolase L1
- Ubiquitin ligase
- Ubiquitin ligases
- Ubiquitin-activating enzyme
- Ubiquitin-binding domains
- Ubiquitin-conjugating enzyme
- Ubiquitin-conjugating enzymes
- Ubiquitin-like proteins
- Ubiquitination
- Ubiquitylation
- Ublituximab
- Ubrogepant
- Udders
- Udenafil
- Uhthoff's phenomenon
- Ulcerative colitis
- Ulcers
- Ulegyria
- Ulerythema
- Ulinastatin
- Ulipristal acetate
- Ulnar
- Ulnar artery
- Ulnar collateral ligament
- Ulnar deviation
- Ulnar nerve
- Ulnar nerve entrapment
- Ulnar neuropathy
- Ulnar notch
- Ulnar styloid process
- Ulnar vein
- Ultimatum game
- Ultra performance liquid chromatography
- Ultra-processed food
- Ultracet
- Ultradian rhythm
- Ultrafiltration
- Ultrafine particles