- Nappy rash
- Narcolepsy
- Nasal congestion
- Nasal polyps
- Natural family planning
- Nausea and vomiting in pregnancy
- Nettle rash
- Neuralgia
- Neurofibromatosis
- Neuromyelitis optica
- Neuropathy, peripheral
- Nits
- Non-insulin-dependent diabetes
- Non-specific urethritis
- Noonan syndrome
- Norovirus
- Nosebleed
- NSAIDs
- Nutrition