- Deafness
- Deer Ticks see Tick Bites
- Degenerative disc disease see Herniated Disc
- Dengue Fever
- Dentistry see Oral Diseases
- Depression
- Dermatitis (Eczema)
- Dermatitis, Allergic
- Dermatitis, Atopic
- Dermatitis, Contact
- Dermatitis Herpetiformis
- Dermatitis, Irritant
- Dermatitis, Perioral
- Dermatitis, Seborrheic
- Dermatology see Skin Diseases
- Dermatomyositis
- Diabetes
- Diabetes in Pregnancy see Gestational Diabetes
- Diagnostic Imaging see Radiology
- Diaper Rash
- Diarrhea
- Diet see Nutrition
- Dieting see Weight Loss
- Digestive System
- Disability
- Disc, Herniated
- Diverticulitis
- Dizziness
- Down Syndrome
- Drug Companies
- Drug Identification Pictures
- Drugs
- Drug Information see Prescription Drug Information
- Duodenal Ulcer see Stomach Ulcers
- Dysentery see Diarrhea
- Dyslexia
- Dysphagia