- Nonfunctioning
- Nonhealing
- Nonimplantation of ovum, causing infertility 628.3
- Noninsufflation, fallopian tube 628.2
- Nonne-Milroy-Meige syndrome (chronic hereditary edema) 757.0
- 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