- Morphine dependence (see also Dependence) 304.0
- Morphinism (see also Dependence) 304.0
- Morphinomania (see also Dependence) 304.0
- Morphoea 701.0
- Morquio (-Brailsford) (-Ullrich) disease or syndrome (mucopolysaccharidosis IV) 277.5
- Morris syndrome (testicular feminization) 259.5
- Morsus humanus (open wound) - see also Wound, open, by site
- Mortification (dry) (moist) (see also Gangrene) 785.4
- Morton's
- Morvan's disease 336.0
- Mosaicism, mosaic (chromosomal) 758.9
- Moschcowitz's syndrome (thrombotic thrombocytopenic purpura) 446.6
- Mother yaw 102.0
- Motion sickness (from travel, any vehicle) (from roundabouts or swings) 994.6
- Mottled teeth (enamel) (endemic) (nonendemic) 520.3
- Mottling enamel (endemic) (nonendemic) (teeth) 520.3
- Mouchet's disease 732.5
- Mould(s) (in vitreous) 117.9
- Moulders'
- Mounier-Kuhn syndrome 748.3
- Mountain
- Mouse, joint (see also Loose, body, joint) 718.1
