- U937
- UAV
- UCHL1
- UCP1
- UCP2
- UDI
- UDP-glucose pyrophosphorylase
- UDP-glucuronosyltransferase
- UGT1A1
- UGT2B7
- ULV
- UMLS
- UNC13A
- UPGMA
- UQCRB
- UQCRC2
- UR-144
- URA3
- URB597
- USAN
- 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
- Ultimatum game
- Ultra performance liquid chromatography
- Ultra-processed food
- Ultracet
- Ultradian rhythm
- Ultrafiltration
- Ultrafine particles
- Ultramicroscope
- Ultramicrotomy
- Ultrasensitivity
- Ultrasonic cleaning
- Ultrasonic wave
- Ultrasonics
- Ultrasonography
- Ultrasound biomicroscopy
- Ultrasound energy
- Ultrasound therapy
- Ultrasound transducer
- Ultrasounds
- Ultrastructure
- Ultraviolet
- Ultraviolet germicidal irradiation
- Ultraviolet light
- Ultraviolet spectrum
- Umbelliferone
- Umbellulone
- Umbilical arteries
- Umbilical artery
- Umbilical cord
- Umbilical cord compression
- Umbilical cord prolapse
- Umbilical fascia
- Umbilical fold
- Umbilical folds
- Umbilical hernia
- Umbilical region
- Umbilical ring
- Umbilical vein
- Umbilical venous catheter
- Umbilicus
- Umbralisib
- Umeclidinium
- Umeclidinium bromide
- Umwelt
- Unani medicine
- Uncanny Valley
- Uncaria
- Uncaria tomentosa
- Uncertainty
- Uncertainty avoidance
- Uncinate fasciculus
- Uncinate process
- Uncombable Hair Syndrome
- Uncombable hair syndrome
- Uncompetitive inhibitor
- Unconditional positive regard
- Unconditioned stimulus
- Unconscious
- Unconsciousness
- Unconventional protein secretion
- Uncoupler
- Uncoupling
- Uncoupling protein
- Uncus
- Undecanal
- Undecaprenyl phosphate
- Underactive bladder
- Underactive thyroid
- Underarm hair
- Underdevelopment
- Undernourishment
- Undernutrition in children
- Understanding
- Undertreatment of pain
- Undifferentiated connective tissue disease
- Undue influence
- Unequal crossing over
- Unethical human experimentation
- Unexplained infertility
- Unfolded protein response
- Ungual
- Unguent
- Unhealthy diet
- UniFrac
- UniGene
- UniProt
- Unicameral bone cyst
- Unicornuate uterus
- Unilamellar liposome
- Unilateral hearing loss
- Unimodal distribution
- Unintended consequences
- Uniparental disomy