- 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
- Mouth - see condition
- Movable
- Movement
- Moya Moya disease 437.5
- Mozart's ear 744.29
- MRSA (methicillin resistant staphylococcus aureus) 041.12
- MSSA (methicillin susceptible staphylococcus aureus) 041.11
- Mu-chain disease 273.2
- Mucha's disease (acute parapsoriasis varioliformis) 696.2
- Mucha-Haberman syndrome (acute parapsoriasis varioliformis) 696.2
- Mucinosis (cutaneous) (papular) 701.8
- Mucocele
- Mucocutaneous lymph node syndrome (acute) (febrile) (infantile) 446.1
- Mucoenteritis 564.9
- Mucolipidosis I, II, III 272.7
