- Deficiency anemias
- Defined daily dose
- Deflagration
- Deflazacort
- Defoamer
- Defoliants
- Deformation
- Degarelix
- Degeneracy
- Degeneration
- Degenerative disc disease
- Degenerative diseases
- Degenerative myopia
- Deglutition
- Degos disease
- Degradation
- Degranulation
- Degree of polymerization
- Degrees of freedom problem
- Dehalogenation
- Dehumanization
- Dehydration
- Dehydroascorbic acid
- Dehydrocholic acid
- Dehydroemetine
- Dehydroepiandrosterone
- Dehydroepiandrosterone sulfate
- Dehydrogenase
- Dehydrogenases
- Deindividuation
- Deinococcus
- Deinococcus radiodurans
- Deinstitutionalisation
- Deinstitutionalization
- Deiodinase
- Deionization
- Deionized water
- Deiters' cells
- Deja vu
- Dejerine-Roussy Syndrome
- Dejerine-Roussy syndrome
- Dejerine-Sottas disease
- Delafloxacin
- Delamanid
- Delavirdine
- Delayed ejaculation
- Delayed graft function
- Delayed gratification
- Delayed grief
- Delayed hemolytic transfusion reaction
- Delayed hypersensitivity
- Delayed implantation
- Delayed milestone
- Delayed pressure urticaria
- Delayed puberty
- Delayed sleep phase disorder
- Delayed sleep phase syndrome
- Deleted in Colorectal Cancer
- Deletion mapping
- Delftia
- Delinquency
- Deliriants
- Delirium
- Delirium tremens
- Delis Kaplan Executive Function System
- Delis-Kaplan Executive Function System
- Delorazepam
- Delta 9 tetrahydrocannabinol
- Delta F508
- Delta cells
- Delta opioid receptor
- Delta ratio
- Delta ray
- Delta rhythm
- Delta sleep inducing peptide
- Delta sleep-inducing peptide
- Delta tocopherol
- Delta waves
- Delta-tocopherol
- Deltacoronavirus
- Deltamethrin
- Deltaretrovirus
- Deltavirus
- Deltoid ligament
- Deltoid muscle
- Deltoid tuberosity
- Deltopectoral groove
- Deltorphin
- Delusional disorder
- Delusional misidentification syndrome
- Delusional parasitosis
- Delusions
- Demand
- Demand characteristics
- Demcizumab
- Demeclocycline
- Dementia
- Dementia praecox
- Dementia with Lewy bodies
- Demethoxycurcumin
- Demethoxyyangonin
- Demethylase
- Demethylating agent
- Demethylation
- Demineralization
- Demineralized bone matrix
- Demodex
- Demodex brevis
- Demodex folliculorum
- Demodicosis
- Demographic and Health Surveys
- Demographic dividend
- Demulcents
- Demyelinating disease
- Demyelinating diseases
- Demyelination
- Denatonium
- Denatonium benzoate
- Denaturation
- Denatured alcohol
- Denatured state
- Denaturing gradient gel electrophoresis
- Denaturing high performance liquid chromatography
- Dendrites
- Dendritic
- Dendritic cells
- Dendritic spines
- Dendroaspis
- Dendrobium nobile
- Dendrograms
- Dendrotoxin
- Denervation
- Denervation supersensitivity
- Dengue
- Dengue fever
- Dengue hemorrhagic fever
- Dengue shock syndrome
- Dengue virus
- Denial
- Denileukin diftitox
- Denitrification
- Denitrifying bacteria
- Denominator data
- Denonvilliers' fascia
- Denopamine
- Denosumab
- Dense breast tissue
- Dense connective tissue
- Dense granules
- Dense irregular connective tissue