N
- NAFLD
- Nail fungus
- Narcissistic personality disorder
- Narcolepsy
- Nasal and paranasal tumors
- Nasal polyps
- Nasopharyngeal carcinoma
- Nearsightedness
- NEC
- Neck pain
- Neonatal jaundice
- Nephroblastoma
- Nephrogenic systemic fibrosis
- Nephrotic syndrome
- Nerve compression
- Nerve sheath tumors
- NET
- Neuralgia, postherpetic
- Neuralgia, trigeminal
- Neurilemmoma
- Neurinomatosis
- Neuroblastoma
- Neurocardiogenic syncope
- Neurodermatitis
- Neuroendocrine carcinoma of the skin
- Neuroendocrine tumors
- Neurofibroma
- Neurofibromatosis type 1
- Neurofibromatosis type 2
- Neurofibromatosis type I
- Neurofibromatosis type II
- Neurofibrosarcoma
- Neuroma, acoustic
- Neuroma, plantar
- Neuromyelitis optica
- Neuromyelitis optica spectrum disorder
- Neuropathy, autonomic
- Neuropathy, diabetic
- Neuropathy, hereditary motor and sensory
- Neuropathy, peripheral
- Nevus
- Newborn jaundice
- NF1
- NF2
- NF2-related schwannomatosis (neurofibromatosis type 2)
- Nickel allergy
- Nicotine addiction
- Nicotine dependence
- Niemann-Pick disease
- Night terrors
- Nightmare disorder
- NMO
- NMOSD
- Noctural enuresis
- Noise-related hearing loss
- Non-Hodgkin lymphoma
- Nonallergic rhinitis
- Nonischemic priapism
- Nonmelanoma skin cancer
- Nontropical sprue
- Nonulcer dyspepsia
- Nonulcer stomach pain
- Noonan syndrome
- Norovirus infection
- Nose fracture
- Nymphomania