- Myalgia (intercostal) 729.1
- Myasthenia 358.00
- Myasthenic 728.87
- Mycelium infection NEC 117.9
- Mycetismus 988.1
- Mycetoma (actinomycotic) 039.9
- Mycobacteriosis - see Mycobacterium
- Mycobacterium, mycobacterial (infection) 031.9
- Mycosis, mycotic 117.9
- Mydriasis (persistent) (pupil) 379.43
- Myelatelia 742.59
- Myelinoclasis, perivascular, acute (postinfectious) NEC 136.9 [323.61]
- Myelinosis, central pontine 341.8
- Myelitis (ascending) (cerebellar) (childhood) (chronic) (descending) (diffuse) (disseminated) (pressure) (progressive) (spinal cord) (subacute) (see also Encephalitis) 323.9
- Myelo-osteo-musculodysplasia hereditaria 756.89
- Myeloblastic - see condition
- Myelocele (see also Spina bifida) 741.9
- Myelocystocele (see also Spina bifida) 741.9
- Myelocytic - see condition
- Myelocytoma 205.1
- Myelodysplasia (spinal cord) 742.59
- Myeloencephalitis - see Encephalitis