- Macular Degeneration
- Major Depressive Disorder
- Malaria
- Male Breast Cancer
- Male Hypogonadism
- Male Infertility
- Mammary Duct Ectasia
- Mastitis
- MCTD
- Measles
- Melanoma
- Membranous Nephropathy
- MEN1
- Meniere's Disease
- Meningioma
- Meningitis
- Menopause
- Menorrhagia (Heavy Menstraul Bleeding)
- Menstrual Cramps
- Mental Illness
- Meralgia Paresthetica
- Merkel Cell Carcinoma
- Mesenteric Ischemia
- Mesenteric Lymphadenitis
- Mesothelioma
- Metabolic Syndrome
- Metal Allergy
- Metatarsalgia
- MGUS
- Microcephaly
- Microscopic Colitis
- Migraine
- Migraine With Aura
- Mild Cognitive Impairment
- Milia
- Milk Allergy
- Miscarriage
- Mitral Valve Disease
- Mitral Valve Prolapse
- Mitral Valve Regurgitation
- Mitral Valve Stenosis
- Mittelschmerz
- MLD
- Molar Pregnancy
- Mold Allergy
- Moles
- Molluscum Contagiosum
- Mononucleosis
- Mood Disorders
- Morning Sickness
- Morphea
- Morton'S Neuroma
- Mosquito Bites
- Mouth Cancer
- Movement Disorders
- Moyamoya Disease
- MPNSTs
- MRSA Infection
- Multiple Myeloma
- Multiple Sclerosis
- Multiple System Atrophy
- Mumps
- Muscle Cramp
- Muscular Dystrophy
- Myasthenia Gravis
- Myelodysplastic Syndromes
- Myelofibrosis
- Myelogenous Leukemia
- Myocardial Ischemia
- Myocarditis
- Myoclonus
- Myofascial Pain Syndrome
- Myositis