Hemophilia A

Medically Reviewed by Renee A. Alli, MD on November 15, 2021
10 min read

Hemophilia A is a condition that keeps your blood from clotting the way it should. That means your body has problems stopping bleeding, both outside and inside your body.

Your condition can be treated, and in some cases you can give yourself the treatment at home. You can lead a full life when you have the right treatment plan in place.

There are different types of hemophilia. With hemophilia A, your body doesn't have enough of a protein called factor VIII, which it needs to make clots and stop bleeding.

Hemophilia A can be mild, moderate, or severe, depending on how little you have of factor VIII. More than half of those with the condition have the severe form.

Hemophilia A usually runs in families, but about one-third of people with the disease don't have a family history of it.

Hemophilia A comes from your genes. You can inherit it from your parents. Or it can happen if a certain gene changes before you're born. This change is called a spontaneous mutation.

The hemophilia A gene mutation happens on the X chromosome. Women get one X chromosome from their mother and one from their father. Men get an X from their mother and a Y from their father.

Most women with the problem gene are carriers and have no symptoms, but they can pass it to their sons. Therefore the disease nearly always shows up in boys, not girls.

A rare type of hemophilia A is acquired hemophilia. It’s most common in people 60 to 80 years of age. If you have this kind, your immune system attacks healthy tissue called clotting factors in your blood. Acquired hemophilia tends to happen alongside these conditions:


The symptoms of hemophilia A depend on whether you have a mild, moderate, or severe case.

Mild hemophilia A. If you're in this group, you may have an episode of heavy bleeding:

  • After you have surgery or another procedure, like having a tooth pulled
  • After childbirth
  • After a serious injury
  • During your period

Some people don't get a diagnosis until after one of these things happens to them when they're adults.

Moderate hemophilia A. Moderate hemophilia usually means you:

  • Bleed a lot when injured
  • Bleed without an injury (spontaneous bleeding)
  • Bruise easily
  • Bleed a lot after a vaccination

Severe hemophilia A. In addition to bleeding after an injury, you may have frequent episodes of bleeding, often into the joints and muscles, without being able to figure out a specific cause.

When you have severe hemophilia A, bleeding can also happen in your brain. It’s rare, but if you have a head bump -- even if it's minor -- and you have any of these symptoms, call your doctor:

  • Prolonged headache
  • Throwing up
  • Sleepiness or tiredness
  • Sudden weakness or problems walking
  • Double vision
  • Convulsions or seizures


If you have a family history of hemophilia and are pregnant, tests can tell if your baby has the disease. There are risks though, so you’ll want to talk to your doctor about testing.

In children, doctors usually diagnose severe cases in the first year of a baby’s life. Does your child bruise easily or bleed for longer than normal from small injuries? Make an appointment with your child's doctor. They can tell if it's hemophilia.

It's unusual for a baby younger than 6 months old to be diagnosed with hemophilia. That's because infants this young usually don't do things that would make them bleed.

Once a baby starts moving, crawling, and bumping into things, you may notice raised bruises, especially on places like the stomach, chest, back, and bottom.

The doctor may ask:

  • What happened to cause the bumps, bruises, and bleeding?
  • How long did the bleeding last?
  • Is your child taking any medications?
  • Are there any other medical concerns you have?
  • What's your family's medical history? Does anyone have a problem with blood clotting?

The doctor may also do blood tests like these, or they may send you to a specialist called a hematologist for them:

  • Complete blood count (CBC). This test looks at the number of different types of cells in your blood as well as your hemoglobin levels to see if bleeding has lowered them.
  • Prothrombin time (PT) and activated partial thromboplastin time (PTT). Both of these tests check how long it takes blood to clot.
  • Factor VIII and factor IX tests, which measure levels of each of those proteins. Factor VIII is for hemophilia A. Factor IX is for hemophilia B, another type of hemophilia.
  • Fibrinogen test. This test shows how well you form clots.
  • Genetic testing, which can help you gauge your chances of having complications from some treatments. And if you're a woman, you'll learn if you're a carrier.


If you or your child is diagnosed with hemophilia, you'll probably have a lot of questions for your doctor, including:

  • How often will you need to visit the doctor?
  • How long is too long to bleed from a small cut?
  • Are some symptoms more serious than others? What are they? And what do you do if you have them?
  • Are there over-the-counter medicines you should or shouldn't use?
  • What treatments does the doctor recommend?
  • How do you keep your child safe? Do you need to limit their activities?
  • Do you need to let teachers and care providers know about their condition?
  • What can you expect as your child gets older?
  • How do you connect with other families that have kids with this condition?
  • What are the chances your other children will have hemophilia? Or that your grandchildren will have it?

The kind of treatment you get depends on a lot of things, including how severe your condition is, how old you are, and your personal needs.

The best place to go for treatment is a federally funded hemophilia treatment center (HTC). You’ll work with a team of specialists, such as surgeons, dentists, physical therapists, and social workers who focus on the blood disorder.

You might need to get regular treatment to prevent bleeding, which you may hear your doctor call "prophylactic" therapy. Or you may need treatment at the time your bleeding happens, which is called "on-demand" therapy.

The goal of treatment is to give you the factor VIII your body doesn't make. That's called factor replacement therapy. It's not a cure, but it does help control your hemophilia.

Replacement therapy works in most cases. But there's a 20% to 30% chance your body will reject it. In that case, your doctors may try different sources for factor VIII, or try different amounts.

There are two types of factor VIII that your doctor may suggest:

  • A "concentrated" version that comes from human blood.
  • A "recombinant" version, which is more common, is made from cells that are genetically engineered to make factor VIII. Some of them have "extended half-lives," which means they can stay in the blood longer.

These products go into your bloodstream through an IV.

If you have mild or moderate hemophilia A, you may be treated with desmopressin (DDAVP). Desmopressin raises the levels of factor VIII in the blood, and you take it through an IV or as a nasal spray.

Drugs known as antifibrinolytics, such as aminocaproic acid and tranexamic acid, can also help if you have a mild form of the disorder. You take them by mouth. They slow the breakdown of clotting factors in the blood.

Emicizumab-kxwh (Hemlibra) is a medicine that can help prevent or reduce the frequency of bleeding episodes in adults and children with hemophilia A. It bridges the gap in the clotting factors left by the missing factor VIII. You take this medication weekly with an injection. A health care professional can give the injection, or you can learn to do it yourself.

Work closely with your doctor if you’re prepping for surgery, travel, pregnancy, or delivery.

Since hemophilia A may mean you get blood donations, you should get vaccinated for hepatitis A and B.

Some new treatments are in clinical trials. If they're approved, they could help you manage your disease with fewer injections. Some might even cure hemophilia A.

One of the most promising treatments in the pipeline is gene therapy. It uses a virus to deliver a normal copy of the mutated gene to your liver cells. The virus is changed first so that it can't make you sick.

Once the new gene is inside your liver, it tells your cells to make factor VIII. With gene therapy, you only need one treatment to fix the problem.

Gene editing is another hemophilia treatment that researchers are studying. It removes or fixes the faulty parts of the gene so that it can tell your body to make the right protein.

Scientists are also looking into cell therapy. It changes liver cells in a lab to make them produce clotting factors. When those cells go into your body, they keep making the clotting factors you need.

Other new treatments in the works could help factor replacement therapy last longer. These treatments could prevent bleeding with fewer injections.

You may notice problems that stem from your hemophilia A, including:

  • Bleeding in deep muscle. This can make your arms and legs swell. The swelling can press on your nerves and lead to numbness or pain.
  • Joint damage. The same pressure from internal bleeding can affect your joints and cause severe pain. If you don’t treat it, you may eventually develop arthritis or your joint could wear away.
  • Infection. Although blood products have become much safer since the 1980s, you’re at a higher risk of receiving contaminated blood because of the number of blood transfusions you may get.
  • Bad reaction to clotting factor treatment. Some people with severe hemophilia have a negative reaction to the clotting factors that treat bleeding. This happens when the immune system makes proteins called inhibitors that turn off the clotting factors. Treatment won’t work as well when this happens.


The severity of hemophilia A doesn't change. Mild, moderate, or severe disease will stay that way your whole life. If your cells can't make clotting factor during childhood, they still won't make it when you're an adult. But your factor levels and how much you bleed can change slightly over time.

Some people with hemophilia A have more bleeding episodes in childhood and during their teen years. By adulthood, these episodes happen less often. People with the mild form of the disease may not have any bleeding episodes until they're adults.

Things like stress or an infection can change your factor levels and cause more bleeding episodes if you have mild hemophilia. You might bleed more after you have surgery or go to the dentist. Your factor level might change slightly, but it should stay in the same range as other people with mild disease.

    Treatments for hemophilia A have improved a lot. They can help you lead a full and active life with the disease.

    Your outlook depends on how much clotting factor your body makes and what other health conditions you have. About half of people with hemophilia A have the severe type, in which their body makes little to no factor VIII.

    Severe disease can cause serious problems like brain bleeding and joint damage. Starting factor replacement therapy early can help prevent these problems. Staying at a healthy weight is another way to protect your joints and prevent complications.

    Your outlook may not be as good if your body rejects the factor.

    You can do a lot to help manage your hemophilia day to day. Keep up with your treatment, follow your doctor's advice, and do these four things:

    1. Handle injuries correctly. Clean small cuts, scrapes, and injuries. Then apply pressure and a bandage. Serious injuries need medical attention.
    2. Tell all your health care professionals that you have (or your child has) hemophilia. Remind them before you schedule any procedures, like dental work. You may need to take medications to help clot your blood beforehand. Keep good dental hygiene so you can help prevent dental work that could cause bleeding.

    Certain medications, like aspirin and other NSAIDs, can slow blood clotting, so check with your doctor about what you should and shouldn't take. Avoid blood thinners. Also check with your doctor about vaccines, like those for hepatitis A and B, that you may need. Most blood products these days are checked for things that can cause disease, but it's still worthwhile to check if you need to take steps to prevent getting infected.

    1. Stay active. Exercise makes you stronger, which makes injuries less likely. It also helps by managing weight -- extra pounds strain the body, which raises the risk of bleeding. Talk with your doctor about what activities you or your child can do.

    Just take some precautions:

    • Children should wear knee pads, elbow pads, and helmets during any activities if they're doing something that might make them fall.
    • Use safety straps in car seats, strollers, and high chairs.
    • Check your home and yard for hazards, like furniture or play equipment with sharp corners.
    1. Learn more about hemophilia. If your child has it, let them know when and how to get help so they feel confident, not scared.


    As a caregiver, you play an important role in helping your loved one manage hemophilia A. You can help your child get the right treatment and prevent bleeding problems. You'll be a better caregiver if you learn about hemophilia A, its symptoms, and how to treat it. Your child's doctor is a good person to ask about these things.

    Make sure your child goes to every doctor visit and takes their medication as prescribed. Learn which sports and other activities are safe to do with hemophilia. Also learn which medications to take for common childhood illnesses and which to avoid.

    Create a care plan. Ask the doctor what to do if your child gets injured and bleeds. Also tell your child's teachers, babysitters, and other caregivers what to do in case of injury.

    Caregiving can be a big job. It's normal to feel tired and burned out when you're trying to manage a loved one's chronic disease.

    Give yourself time for breaks during the day. Take a walk, watch a movie, or do something else to help yourself. If you feel overwhelmed, ask for help from loved ones, a social worker, or a counselor.

    Many other people have hemophilia, and their advice can be helpful and inspiring, especially if you're just starting to get familiar with the condition.

    The National Hemophilia Foundation can connect you to a treatment center near you and to support groups.

    The federal government pays for a network of more than 140 hemophilia treatment centers where you can get treatment, education, and other resources you need.