- Nonovulation 628.0
- Nonpatent fallopian tube 628.2
- Nonpneumatization, lung NEC 770.4
- Nonreflex bladder 596.54
- Nonretention of food - see Vomiting
- Nonrotation - see Malrotation
- Nonsecretion, urine (see also Anuria) 788.5
- Nonunion
- Nonviability 765.0
- Nonvisualization, gallbladder 793.3
- Nonvitalized tooth 522.9
- Normal
- Normoblastosis 289.89
- Normocytic anemia (infectional) 285.9
- Norrie's disease (congenital) (progressive oculoacousticocerebral degeneration) 743.8
- North American blastomycosis 116.0
- Norwegian itch 133.0
- Nose, nasal - see condition
- Nosebleed 784.7
- Nosomania 298.9
- Nosophobia 300.29
- Nostalgia 309.89
