- Macacus ear 744.29
- Maceration
- Machado-Joseph disease 334.8
- Machupo virus hemorrhagic fever 078.7
- Macleod's syndrome (abnormal transradiancy, one lung) 492.8
- Macrocephalia, macrocephaly 756.0
- Macrocheilia (congenital) 744.81
- Macrochilia (congenital) 744.81
- Macrocolon (congenital) 751.3
- Macrocornea 743.41
- Macrocytic - see condition
- Macrocytosis 289.89
- Macrodactylia, macrodactylism (fingers) (thumbs) 755.57
- Macrodontia 520.2
- Macroencephaly 742.4
- Macrogenia 524.05
- Macrogenitosomia (female) (male) (praecox) 255.2
- Macrogingivae 523.8
- Macroglobulinemia (essential) (idiopathic) (monoclonal) (primary) (syndrome) (Waldenström's) 273.3
- Macroglossia (congenital) 750.15
- Macrognathia, macrognathism (congenital) 524.00
- Macrogyria (congenital) 742.4