- Dandruff
- Date rape drugs
- Deafblindness
- Deafness
- Decongestant drugs
- Deep vein thrombosis
- Dehydration
- Dementia
- Dengue
- Dental abscess
- Dental care for babies and children
- Dental decay (dental caries)
- Dental fluorosis
- Dentures (false teeth)
- Depression
- Dermatitis herpetiformis
- Dermatochalasis
- Detached retina
- Developmental coordination disorder
- Devic's disease
- DEXA scan
- Diabetes
- Diabetes, gestational
- Diabetes insipidus
- Diabetes, type 1
- Diabetes, type 2
- Diabetic retinopathy
- Dialysis
- Diaphragms and caps
- Diarrhoea
- Diarrhoea and sickness in children
- Differential test
- Digital Rectal Examination
- Dilatation and curettage (D&C)
- Diphtheria
- Diphyllobothrium latum
- Diplopia
- Discoid eczema
- Dislocated shoulder
- Diverticular disease and diverticulitis
- Dizziness
- Double vision
- Down's syndrome
- Drink spiking