- Mucopolysaccharidosis (types 1-6) 277.5
- Mucormycosis (lung) 117.7
- Mucosa associated lymphoid tissue (MALT) 200.3
- Mucositis - see also Inflammation, by site 528.00
- Mucous - see also condition
- Mucoviscidosis 277.00
- Mucus
- Muguet 112.0
- Mulberry molars 090.5
- Müllerian mixed tumor (M8950/3) - see Neoplasm, by site, malignant
- Multicystic kidney 753.19
- Multilobed placenta - see Placenta, abnormal
- Multinodular prostate 600.10
- Multiparity V61.5
- Multipartita placenta - see Placenta, abnormal
- Multiple, multiplex - see also condition
- Mumps 072.9
- Mumu (see also Infestation, filarial) 125.9
- Münchausen syndrome 301.51
- Münchmeyer's disease or syndrome (exostosis luxurians) 728.11
- Mural - see condition
- Murmur (cardiac) (heart) (nonorganic) (organic) 785.2
