Breast cancer can affect anyone. Learn about the signs and symptoms of this cancer. Treatment most often involves surgery.
Disease
Mantle cell lymphoma
Find out more about the symptoms, diagnosis and treatment of this type of non-Hodgkin lymphoma.
Disease
Menstrual cramps
Menstrual cramps — pain in the lower abdomen just before or during menstrual periods — can range from mild to severe. Learn about treatment options.
Disease
Merkel cell carcinoma
Learn about this skin cancer that grows quickly. Find out about symptoms, diagnosis and treatments, including Mohs surgery, radiation and immunotherapy.
Disease
Metastatic (stage 4) prostate cancer
Find out about diagnosis and treatment of this cancer that has spread to the lymph nodes or other parts of the body.
Disease
Microscopic colitis
Ongoing, watery diarrhea could be a sign of this condition of the colon. Find out about testing and treatment.
Disease
Mild cognitive impairment (MCI)
Learn more about this stage between the typical memory loss related to aging and the more serious decline of dementia.
Disease
Mixed connective tissue disease
Mixed connective tissue disease has signs and symptoms of multiple disorders, making it difficult to diagnose. There's no cure, but medications can help.
Disease
Molluscum contagiosum
Learn how to prevent and treat this common skin infection that affects people of all ages.
Disease
Mouth cancer
Learn what healthcare professionals look for when diagnosing mouth cancer. Find out about oral cancer treatments, including surgery, chemotherapy and radiation.
Disease
Multisystem inflammatory syndrome in children (MIS-C) and COVID-19
Learn about symptoms of MIS-C, a serious condition linked to coronavirus disease 2019 (COVID-19). Get help fast if your child shows any signs.
Disease
Muscle cramp
Learn about this sudden, painful tightening of a muscle and what to do about it.