- Nephropyosis (see also Abscess, kidney) 590.2
- Nephrorrhagia 593.81
- Nephrosclerosis (arteriolar) (arteriosclerotic) (chronic) (hyaline) (see also Hypertension, kidney) 403.90
- Nephrosis, nephrotic (Epstein's) (syndrome) 581.9
- Nephrosonephritis hemorrhagic (endemic) 078.6
- Nephrostomy status V44.6
- Nerve - see condition
- Nerves 799.21
- Nervous (see also condition) 799.21
- Nervousness 799.21
- Nesidioblastoma (M8150/0)
- Netherton's syndrome (ichthyosiform erythroderma) 757.1
- Nettle rash 708.8
- Nettleship's disease (urticaria pigmentosa) 757.33
- Neumann's disease (pemphigus vegetans) 694.4
- Neuralgia, neuralgic (acute) (see also Neuritis) 729.2
- Neurapraxia - see Injury, nerve, by site
- Neurasthenia 300.5
- Neurilemmoma (M9560/0) - see also Neoplasm, connective tissue, benign
- Neurilemmosarcoma (M9560/3) - see Neoplasm, connective tissue, malignant
- Neurilemoma - see Neurilemmoma
- Neurinoma (M9560/0) - see Neurilemmoma
