- Negri bodies 071
- Neisserian infection NEC - see Gonococcus
- Nematodiasis NEC (see also Infestation, Nematode) 127.9
- Neoformans cryptococcus infection 117.5
- Neonatal - see also condition
- Neonatorum - see condition
- Neovascularization
- Nephralgia 788.0
- Nephritis, nephritic (albuminuric) (azotemic) (congenital) (degenerative) (diffuse) (disseminated) (epithelial) (familial) (focal) (granulomatous) (hemorrhagic) (infantile) (nonsuppurative, excretory) (uremic) 583.9
- Nephroblastoma (M8960/3) 189.0
- Nephrocalcinosis 275.49
- Nephrocystitis, pustular (see also Pyelitis) 590.80
- Nephrolithiasis (congenital) (pelvis) (recurrent) 592.0
- Nephroma (M8960/3) 189.0
- Nephronephritis (see also Nephrosis) 581.9
- Nephronopthisis 753.16
- Nephropathy (see also Nephritis) 583.9
- Nephroptosis (see also Disease, renal) 593.0
- 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