Diagnosaurus
- Dandruff
- Dark urine
- Deafness
- Death, sudden
- Decubitus ulcers
- Deep-vein thrombosis
- Degenerative joint disease
- Delirium
- Delusional disorder
- Dementia
- Dengue
- Depigmentation
- Depression
- Dermatitis, atopic
- Dermatitis, contact
- Dermatitis, exfoliative
- Dermatitis, seborrheic
- Dermatitis medicamentosa
- Dermatology, general DDx
- Dermatomyositis
- Dermatophytid reaction
- Dermatophytosis
- Desquamative erythema
- Diabetes insipidus
- Diabetes mellitus
- Diabetic ketoacidosis
- Diabetic nephropathy
- Diabetic retinopathy
- Diarrhea, acute
- Diarrhea, chronic
- Diarrhea, malabsorption
- Diarrhea, traveler's
- Diarrhea in diabetes
- Diarrhea in HIV/AIDS
- Diastolic murmur
- DIC
- Diffusion capacity decreased on PFTs
- Diffusion capacity increased on PFTs
- Digitalis overdose
- Dilated cardiomyopathy, primary
- Dilated pupil
- Diphtheria
- Diplopia
- Discoid eczema
- Discoid lupus erythematosus
- Disk herniation, lumbar
- Dissection, aortic
- Dissection, carotid
- Disseminated intravascular coagulation
- Diverticulitis
- Diverticulosis
- Dizziness
- DLCO decreased on PFTs
- DLCO increased on PFTs
- Double vision
- Down syndrome
- Dracunculiasis (Guinea worm infection)
- Drowning
- Drug eruption
- Drug eruption, fixed
- Dry eyes
- Dry mouth
- Duodenal ulcer
- Dupuytren's contracture
- Dysarthria
- Dysentery, bacillary
- Dysequilibrium
- Dysfunctional uterine bleeding
- Dyshidrotic eczema
- Dysmenorrhea
- Dyspareunia
- Dyspepsia
- Dysphagia
- Dyspnea
- Dyspnea, episodic
- Dyspnea, nocturnal
- Dystonia
- Dysuria