Diagnosaurus
- Nail disorders, miscellaneous
- Nail disorders, onycholysis
- Nails, discolored or thick
- Nails, distorted
- Nasal congestion
- Nasal deformity
- Nasal polyps
- Nasal septum perforation
- Nasal tumors
- NASH
- Nausea
- Nausea and fever
- Neck mass
- Neck pain
- Neck pain and fever
- Neck stiffness
- Nephritic syndrome
- Nephrolithiasis
- Nephrotic syndrome
- Neurocysticercosis
- Neurodermatitis, circumscribed
- Neurofibromatosis
- Neurogenic arthropathy
- Neurogenic bladder
- Neuropathy, peripheral (mononeuropathy)
- Neuropathy, peripheral (polyneuropathy)
- Neutropenia
- Neutropenic fever
- Neutrophilia
- Nevi
- Nipple discharge
- Nipple discharge, milky
- Nipple or areolar lesions
- Nocardiosis
- Nocturia
- Nocturnal dyspnea
- Nocturnal leg cramps
- Nodules, subcutaneous
- Nodules, thyroid
- Nodules and papules
- Nonalcoholic fatty liver disease
- Non-Hodgkin's lymphoma
- Nonpalpable purpura
- Normal pressure hydrocephalus
- Normocytic anemia
- Nosebleed
- Nosocomial fever
- Nummular eczema or dermatitis
- Nystagmus