Anaphylaxis, a severe allergic reaction, is an emergency. Learn who's at risk, what to watch for and what to do when it occurs.
Disease
Anemia
Having too few healthy red blood cells causes tiredness and weakness. There are many types of this condition.
Disease
Angelman syndrome
Learn about this genetic disorder that causes developmental delays, problems with speech and other symptoms.
Disease
Angina
Learn about a type of chest pain caused by reduced blood flow to the heart. This chest pain is a symptom of heart disease.
Disease
Angiosarcoma
Learn about this rare cancer that begins in the blood vessels and lymph vessels. Treatments include surgery, radiation therapy and chemotherapy.
Disease
Ankylosing spondylitis
Learn about this inflammatory disease that can cause some of the vertebrae in the spine to fuse over time.
Disease
Anorexia nervosa
People with this eating disorder have a very low body weight, an intense fear of gaining weight and a flawed way of seeing their body.
Disease
Anorgasmia in women
Anorgasmia is regular difficulty having an orgasm after plenty of sexual stimulation. It affects many women, causing distress.
Disease
Anterior vaginal prolapse (cystocele)
This condition happens when the pelvic floor muscles weaken and the bladder pushes into the front part of the vagina. Learn how it's treated..
Disease
Anthrax
Learn about the symptoms and risks of anthrax, a rare but deadly bacterial disease that's been used in bioterrorism.
Disease
Antibiotic-associated diarrhea
Learn more about why you might get diarrhea while taking antibiotics, as well as how to treat or prevent this uncomfortable and sometimes serious problem.
Disease
Antiphospholipid syndrome
Learn about causes and treatment of this blood disorder that mainly affects women and may cause blood clots and miscarriages.