- De Quervain’s tenosynovitis
- Deep vein thrombosis
- Dehydration
- Depression
- Dermatitis
- Dermatographia
- Dermatomyositis
- Desmoid tumors
- Deviated septum
- Diabetes
- Diabetes insipidus
- Diabetic coma
- Diabetic hyperosmolar syndrome
- Diabetic hypoglycemia
- Diabetic ketoacidosis
- Diabetic nephropathy
- Diabetic neuropathy
- Diabetic retinopathy
- Diagnostic paracentesis
- Diarrhea