- Ixazomib
- Ixekizumab
- Ixodes holocyclus
- Ixodes scapularis
- Ixodida
- Ixodidae
- IκB kinase
- IκBα
- J chain
- J wave
- JAG1
- JAK-STAT signaling pathway
- JAK1
- JAK3
- JAM
- JARID2
- JASPAR
- JAWS
- JC virus
- JMJD1C
- JND
- JNK
- JPLS
- JQ1
- JUNB
- JUPITER trial
- JWH-018
- JWH-073
- JZL184
- Jabuticaba
- Jaccoud's arthropathy
- Jacobsen syndrome
- Jadad scale
- Jag1
- James Lind Alliance
- James-Lange theory
- Jamestown Canyon virus
- Jamshidi needle
- Jamu
- Janeway lesions
- Janus Green
- Janus kinase
- Janus kinase 1
- Janus kinase 3
- Janus kinase inhibitor
- Japanese encephalitis
- Japanese encephalitis vaccine
- Jarisch Herxheimer reaction
- Jarisch-Herxheimer reaction
- Jasminum grandiflorum
- Jasminum officinale
- Jasmonate
- Jasmonic acid
- Jatropha
- Jatrorrhizine
- Jaundice
- Jaw
- Jaw claudication
- Jaw jerk reflex
- Jaw thrust maneuver
- Jaw-thrust maneuver
- Jejunoileal bypass
- Jejunojejunostomy
- Jejunostomy
- Jejunum
- Jell-O
- Jendrassik maneuver
- Jenkins activity survey
- Jervell and Lange-Nielsen syndrome
- Jervine
- Jeryl Lynn
- Jet injectors
- Jet lag
- Jet ventilation
- Jeune syndrome
- Jing
- Jivi
- Job demands-resources model
- Jock itch
- Jockstrap
- Jogging
- Johanson-Blizzard Syndrome
- Johanson-Blizzard syndrome
- John Henryism
- Joint
- Joint attention
- Joint capsule
- Joint contracture
- Joint dislocation
- Joint distribution
- Joint effusion
- Joint manipulation
- Joint mobilization
- Joint probability
- Joint replacement
- Joint stability
- Joint stiffness
- Joint swelling
- Jojoba
- Josamycin
- Joubert syndrome
- Joule Thomson effect
- Juglans regia
- Jugular foramen
- Jugular fossa
- Jugular tubercle
- Jugular vein
- Jugular venous pressure
- Jujube
- July effect
- Jumping
- Jumping jacks
- Jumping to conclusions
- JunD
- Junb
- Junctional diversity
- Junctional epidermolysis bullosa
- Junctional epithelium
- Junctional nevus
- Junctional rhythm
- Junctional tachycardia
- Juncus effusus
- Junin virus
- Juniper berry
- Juniperus communis
- Junk DNA
- Jurkat cells
- Just-world hypothesis
- Justifiable homicide
- Juvenile
- Juvenile Polyposis Syndrome
- Juvenile arthritis
- Juvenile dermatomyositis
- Juvenile idiopathic arthritis
- Juvenile myelomonocytic leukemia
- Juvenile myoclonic epilepsy
- Juvenile nephronophthisis
- Juvenile osteoporosis
- Juvenile polyposis syndrome
- Juvenile primary lateral sclerosis
- Juvenile rheumatoid arthritis
- Juvenile xanthogranuloma
- Juvenile-hormone esterase
- Juxtacrine signalling
- Juxtaglomerular apparatus
- Juxtaglomerular cells
- K complexes
- K-SADS
- K-casein
- K-edge