- Macular Degeneration
- Magnesium Imbalance
- Magnetic Field Therapy
- Magnetic Resonance Imaging
- Malabsorption Syndrome
- Malaria
- Malignant Lymphomas
- Malignant Melanoma
- Malingering
- Mallet Finger
- Mallory-Weiss Syndrome
- Malnutrition
- Malocclusion
- Malt Lymphoma
- Mammography
- Mania
- Marfan syndrome
- Marijuana
- Marriage counseling
- Marshall-Marchetti-Krantz procedure
- Massage therapy
- Mastectomy
- Mastitis
- Mastocytosis
- Mastoidectomy
- Mastoiditis
- Maxillofacial Trauma
- Measles
- Meckel's Diverticulum
- Mediastinoscopy
