Diseases and Conditions

Find doctor-approved information about symptoms, causes, diagnosis, treatment and prevention of common diseases and conditions.


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All conditions that start with the letter H
  • Young woman wearing a mask to protect from getting H1N1 influenza

    H1N1 Influenza

    H1N1 influenza is a viral infection. It’s not the same as seasonal flu (influenza). The first outbreak occurred in 2009…

  • A man looking in the mirror at his receding hairline

    Hair Loss

    It is normal to shed some hair each day as part of this cycle. However, some people may experience excessive…

  • A man scraping his tongue with a tongue scraper


    Learn about what causes halitosis and what you can do to prevent it.

  • Hammer Toe

    When a person has hammer toe, the end of their toe bends downward and the middle joint curls up. Over…

  • Hand, foot, and mouth disease

    Hand, foot, and mouth disease is a contagious childhood illness. It causes sores inside and outside the mouth as well…

  • woman holding throat in pain

    Hashimoto's Disease

    Hashimoto’s disease is an autoimmune disease that affects your thyroid gland.

  • A woman with a head injury being checked by a doctor

    Head Injuries

    Head injuries can cause harm to your brain, skull, or scalp. There are many types including concussion, brain contusion, skull…

  • Head Lice

    Head lice are small wingless insects that can get on your hair and scalp. Lice bites may cause constant scratching,…

  • woman with a headache holds a hand to her head


    There are several different types of headaches. Migraines and tension headaches are the most common.

  • young Asian boy with hearing device in ear

    Hearing Problems in Children

    Hearing loss in children can be caused by a number of factors. Recognizing the symptoms early increases the chances of…

  • An older man bent over in pain holding his chest

    Heart Attack

    A heart attack is a cardiac event caused by one or several factors and can be mild or fatal.

  • side-by-side diagrams of a healthy heart and one with heart failure

    Heart Failure

    Heart failure means your heart isn’t pumping blood as well as it should. It can be caused by different heart…

  • Doctor listens to young girl’s heartbeat

    Heart Murmurs

    A heart murmur is an abnormal noise between heartbeats. It can be a sign of a heart problem.

  • photo of an electrocardiogram ecg or ekg printout with stethoscope

    Heart Palpitations

    Heart palpitations is a condition that feels like your heart is pounding, racing, or skipping beats (fluttering).

  • A woman pressing on her chest due to heartburn pain


    Heartburn is a burning feeling in the lower chest, along with a sour taste in the throat and mouth. It…

  • Senior man with heat exhaustion cools his head with a wet cold cloth

    Heat Exhaustion and Heat Stroke

    Heat exhaustion and heatstroke are serious conditions. Learn the warning signs of these heat-related illnesses, as well as how to…

  • Heat Rash

    Heat rash is a skin irritation that stings and makes your skin red. It is also called miliaria or prickly…

  • doctor checks blood pressure of a pregnant woman

    HELLP Syndrome

    HELLP Syndrome is a rare but serious pregnancy-related illness, similar to preeclampsia, another pregnancy condition.

  • illustration of red blood cells in the bloodstream and Hemolytic uremic syndrome (HUS)

    Hemolytic Uremic Syndrome

    Hemolytic Uremic Syndrome is a condition that results from a digestive system infection.

  • Hemorrhoids

    Hemorrhoids are swollen veins in your rectum or anus. The type of hemorrhoid you have depends on where it occurs…