Diagnosaurus
- Nail disorders, onycholysis
- Nasal congestion
- Nasal polyps
- Nasal septum perforation
- Nasal tumors
- NASH
- Nephritic syndrome
- Nephrolithiasis
- Nephrotic syndrome
- Neurocysticercosis
- Neurodermatitis, circumscribed
- Neurofibromatosis
- Neurogenic arthropathy
- Neurogenic bladder
- Neuropathy, peripheral (mononeuropathy)
- Neuropathy, peripheral (polyneuropathy)
- Neutropenia
- Nevi
- Nipple discharge, milky
- Nocardiosis
- Nonalcoholic fatty liver disease
- Non-Hodgkin's lymphoma
- Normal pressure hydrocephalus
- Normocytic anemia
- Nummular eczema or dermatitis