• Macular Degeneration

• Malabsorption

• Malaria

• Malignant Histiocytosis (T-Cell Lymphoma)

• Malnutrition

• Marfan Syndrome

• Mastitis

• Measles

• Meckel's Diverticulum

• Melanoma

See also: Skin Cancer

• Memory Loss

• Meniere's Disease

• Meningioma

• Meningitis

• Meniscus Tears

• Menopause

• Menstrual Cramps

• Menstrual Periods

• Mental Retardation

• Mesenteric Artery Ischemia - See Mesenteric Vascular Disease

• Mesenteric Vascular Disease

• Mesothelioma

• Metabolic Syndrome

• Metastatic Brain Cancer - See Brain Metastases

• Metastatic Cancer of Unknown Primary Site

• Metastatic Pleural Tumors

• Migraine

• Milk Intolerance - See Lactose Intolerance

• Miscarriage

• Mitochondrial Myopathies

• Mitral Regurgitation

• Mitral Stenosis

• Mitral Valve Prolapse

• Mittelschmerz

• Moles (Nevi)

• Molluscum Contagiosum

• Mono - See Mononucleosis

• Mononucleosis

• Morning Sickness

• Morton's Neuroma

• Motion Sickness

• Mouth Cancer - See Head and Neck Cancer

• Mouth Ulcers

• MRSA (Methicillin-Resistant Staphylococcus aureus) - See Antibiotic-Resistant Infections

• Multiple Myeloma - See Plasma Cell Myeloma

• Multiple Sclerosis

• Multiple System Atrophy

• Mumps

• Munchausen Syndrome

• Munchausen Syndrome by Proxy

• Murmur - See Heart Murmur

• Muscle Cramps

• Muscular Dystrophy

• Myalgic Encephalomyelitis - See Chronic Fatigue Syndrome

• Myasthenia Gravis

• Myasthenic Syndrome - See Lambert-Eaton Myasthenic Syndrome

• Myelodysplastic/Myeloproliferative Disorders

• Myocarditis

• Myofascial Pain

• Myopia

• Myositis

• Myxedema - See Hypothyroidism