- Macacus... to Macrogyria...
- Macrohydrocephalus... to Majocchi...
- Major... to Malherbe...
- Malibu... to Mammillitis...
- Mammitis... to March...
- Marchand... to Marshall...
- Martin... to Masturbation...
- Maternal... to Meconium...
- Median... to Megalencephaly...
- Megalerythema... to Meige...
- Melalgia... to Melioidosis...
- Melitensis... to Meninges...
- Meningioma... to Menkes...
- Menolipsis... to Merycism...
- Merzbacher... to Metamorphopsia...
- Metaplasia... to Mibelli...
- Mice... to Microgenitalia...
- Microglioma... to Microvillus...
- Micturition... to Millard...
- Miller... to Misdirection...
- Mismanagement... to Molarization...
- Mold... to Monocytopenia...
- Monocytosis... to Morgagni...
- Morgagni... to Mottling...
- Mouchet... to Mucopolysaccharidosis...
- Mucormycosis... to Murri...
- Muscae... to Myelinosis...
- Myelitis... to Myelopathic...
- Myelopathy... to Myodiastasis...
- Myoendocarditis... to Myosis...
- Myopathy... to Myxosarcoma...