- Nail abnormalities
- Nail patella syndrome
- Narcolepsy
- Nasal cancer
- Nasal congestion
- Nasal polyps
- Nasopharyngeal cancer
- Neck pain
- Neck stiffness
- Necrotising fasciitis
- Neonatal herpes (herpes in a newborn baby)
- Neonatal respiratory distress syndrome
- Nephrotic syndrome in children
- Nettle rash
- Neuralgia, postherpetic
- Neuralgia, trigeminal
- Neuroblastoma
- Neuroendocrine tumours
- Neurofibromatosis type 1
- Neurofibromatosis type 2
- Neuromyelitis optica
- Neuropathy, peripheral
- Neutropenia (white blood cell deficiency)
- Night sweats
- Night terrors
- Nightmares
- Nipple discharge
- Nits
- Nocturnal enuresis
- Noise intolerance (hyperacusis)
- Non-alcoholic fatty liver disease (NAFLD)
- Non-alcoholic steatohepatitis (NASH)
- Non-allergic rhinitis
- Non-gonococcal urethritis
- Non-Hodgkin lymphoma
- Non-insulin-dependent diabetes
- Non-specific urethritis
- Non-steroidal anti-inflammatory drugs
- Noonan syndrome
- Norovirus
- Nose and sinus cancer
- Nosebleed
- NSAIDs
- Nummular eczema
