- Migraine (idiopathic) 346.9
- Migrant, social V60.0
- Migratory, migrating - see also condition
- Mikulicz's disease or syndrome (dryness of mouth, absent or decreased lacrimation) 527.1
- Milian atrophia blanche 701.3
- Miliaria (crystallina) (rubra) (tropicalis) 705.1
- Miliary - see condition
- Milium (see also Cyst, sebaceous) 706.2
- Milk
- Milk-leg (deep vessels) 671.4
- Milkers' nodes 051.1
- Milkman (-Looser) disease or syndrome (osteomalacia with pseudofractures) 268.2
- Milky urine (see also Chyluria) 791.1
- Millar's asthma (laryngismus stridulus) 478.75
- Millard-Gubler paralysis or syndrome 344.89
- Millard-Gubler-Foville paralysis 344.89
- Miller Fisher's syndrome 357.0
- Miller's disease (osteomalacia) 268.2
- Miller-Dieker syndrome 758.33
- Milles' syndrome (encephalocutaneous angiomatosis) 759.6
- Mills' disease 335.29
- Millstone makers' asthma or lung 502