- Diphencyprone
- Diphenhydramine
- Diphenhydramine hydrochloride
- Diphenidine
- Diphenoxylate
- Diphenyl disulfide
- Diphenylamine
- Diphenylbutylpiperidine
- Diphenylcarbazone
- Diphenylcyclopropenone
- Diphosphate
- Diphthamide
- Diphtheria
- Diphtheria antitoxin
- Diphtheria toxin
- Diphtheria toxoid
- Diphtheria vaccine
- Diphyllobothrium
- Diphyllobothrium latum
- Dipicolinic acid
- Dipipanone
- Dipivefrine
- Diplegia
- Diplococcus
- Diploe
- Diploic veins
- Diploidy
- Diplophonia
- Diplopia
- Diplopterys cabrerana
- Dipolar coupling
- Dipole moment
- Dipotassium hydrogen phosphate
- Diprenorphine
- Dipropyltryptamine
- Dipsomania
- Diptericin
- Dipyridamole
- Diquat
- Dira
- Diradicals
- Direct Analysis in Real Time
- Direct DNA damage
- Direct agglutination test
- Direct fluorescent antibody
- Direct immunofluorescence
- Direct instruction
- Direct pathway
- Direct repeat
- Direct thrombin inhibitors
- Direct-acting antivirals
- Directed differentiation
- Directed therapy
- Directing groups
- Directional hearing
- Directionality
- Directly observed therapy
- Dirofilaria
- Dirofilaria immitis
- Dirofilariasis
- Dirt
- Disability
- Disability adjusted life years
- Disability and poverty
- Disability-adjusted life year
- Disaccharidases
- Disaccharides
- Disarticulation
- Disaster medicine
- Disaster preparedness
- Disaster psychiatry
- Disc protrusion
- Disc shedding
- Disc1
- Discectomy
- Discitis
- Disclosing tablets
- Discogenic pain
- Discoid lupus erythematosus
- Discoidin
- Discoidin domain
- Disconnection syndrome
- Discovery
- Discovery learning
- Discovery of nuclear fission
- Discrete dipole approximation
- Discrimination testing
- Discriminative stimulus
- Disease X
- Disease burden
- Disease clusters
- Disease control
- Disease ecology
- Disease gene identification
- Disease management
- Disease model
- Disease model of addiction
- Disease modifying antirheumatic drugs
- Disease modifying therapy
- Disease mongering
- Disease of despair
- Disease ontology
- Disease outbreaks
- Disease resistance
- Disease specific survival
- Disease surveillance
- Disease transmission
- Disease-free survival
- Disease-modifying antirheumatic drugs
- Diseases of affluence
- Diseases of poverty
- Diseases of the nervous system
- Disequilibrium
- Disgust
- Dishabituation
- Disinfectants
- Disinfection
- Disinhibition
- Dislocations
- Dismutase
- Disodium phosphate
- Disomy
- Disopyramide
- Disorder of sex development
- Disordered eating
- Disorders of calcium metabolism
- Disorders of consciousness
- Disorders of sex development
- Disorganized attachment
- Disorganized schizophrenia
- Disorientation
- Disparity
- Dispase
- Dispensary
- Dispersants
- Dispersing agent
- Dispersion
- Dispersion medium
- Dispersion staining
- Dispersity
- Displaced aggression
- Displacement
- Display rules
- Displays
- Disposable equipment
- Disposition index
- Disproportionation
- Disruptive mood dysregulation disorder
- Dissecting aneurysm
- Dissecting aortic aneurysm