- Molluscum
- Mönckeberg's arteriosclerosis, degeneration, disease, or sclerosis (see also Arteriosclerosis, extremities) 440.20
- Monday fever 504
- Monday morning dyspnea or asthma 504
- Mondini's malformation (cochlea) 744.05
- Mondor's disease (thrombophlebitis of breast) 451.89
- Mongolian, mongolianism, mongolism, mongoloid 758.0
- Monilethrix (congenital) 757.4
- Monilia infestation - see Candidiasis
- Moniliasis - see also Candidiasis
- Monkeypox 057.8
- Monoarthritis 716.60
- Monoblastic - see condition
- Monochromatism (cone) (rod) 368.54
- Monocytic - see condition
- Monocytopenia 288.59
- Monocytosis (symptomatic) 288.63
- Monofixation syndrome 378.34
- Monomania (see also Psychosis) 298.9
- Mononeuritis 355.9
- Mononeuropathy (see also Mononeuritis) 355.9
- Mononucleosis, infectious 075
