Hemophilia is a rare, genetic blood disorder that happens when your blood doesn’t clot and make your bleeding slow down or stop. Hemophilia happens when people don’t have the normal amount of clotting factors. Clotting factors help blood clot. Healthcare providers treat hemophilia by replacing missing clotting factors.


Clotting factors are proteins in your blood that work with your platelets (top) to stop or slow bleeding.
Hemophilia happens when you don’t have enough clotting factors to help control how much you bleed. People with hemophilia may bleed for no apparent reason. They may bleed more than normal after being injured or having surgery. Clotting factors are proteins in your blood that work with your platelets (top) to stop or slow bleeding. Without clotting factors, you may have excessive or uncontrollable bleeding.

What is hemophilia?

Hemophilia is a rare, inherited blood disorder that causes your blood to clot less, which results in an increased risk of bleeding or bruising.

Hemophilia happens because your body doesn’t make enough protein (clotting factors) to help your blood form clots. Clotting factors are proteins in your blood. They work with your platelets to form blood clots that control bleeding. Low clotting factor levels increase bleeding risk.

There are several types of hemophilia. Hemophilia may be severe, moderate or mild based on the amount of clotting factor in your blood.

Healthcare providers treat this condition by replacing the missing clotting factor. There isn’t a cure for hemophilia, but people who receive treatment generally live nearly as long as people who don’t have hemophilia. Providers are researching gene therapy and gene replacement therapy as new ways to treat and possibly cure hemophilia.

Can people develop hemophilia?

Yes, but that rarely happens. Acquired hemophilia, or hemophilia that isn’t inherited, develops when autoantibodies start to attack a specific clotting factor. (Antibodies are protective proteins your immune system makes. Autoantibodies attack antibodies, essentially attacking your body’s own cells, tissues and proteins.)


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Is hemophilia a common disease?

No, it’s not. According to the U.S. Centers for Disease Control and Prevention (CDC) in August 2022, about 33,000 people in the U.S. have hemophilia. Hemophilia typically affects men and people assigned male at birth (AMAB). Rarely, women and people assigned female at birth (AFAB) may have clotting factor levels that are so low that they develop symptoms such as having very heavy periods.

What are hemophilia types?

There are three types of hemophilia:

  • Hemophilia A: This is the most common type of hemophilia. It happens when you don’t have enough clotting factor 8 (factor VIII). The CDC estimates about 10 in 100,000 people have hemophilia A.
  • Hemophilia B: Hemophilia B happens when you don’t have enough clotting factor 9 (factor IX.) The CDC estimates about 3 in 100,000 people in the U.S. have hemophilia B.
  • Hemophilia C: Hemophilia C is also known as factor 11 (factor XI) deficiency. This hemophilia type is very rare, affecting 1 in 100,000 people.

Is hemophilia a serious illness?

It can be. People with severe hemophilia may develop life-threatening bleeding, but they’re more likely to develop bleeding in their muscles and joints.

Symptoms and Causes

What are hemophilia symptoms?

The most significant symptom is unusual or excessive bleeding or bruising.

  • People with hemophilia may develop large bruises after minor injuries. This is a sign of bleeding under their skin.
  • They may bleed for an unusually long time, whether that’s bleeding after surgery, bleeding after dental treatment or simply bleeding from a cut finger.
  • They may start bleeding for no apparent reason, such as sudden bloody noses.

How much bruising or bleeding people have depends on whether they have severe, moderate or mild hemophilia:

  • People with severe hemophilia often have spontaneous bleeding or bleeding for no apparent reason.
  • People with moderate hemophilia who have serious injuries may bleed for an unusually long time.
  • People with mild hemophilia may have unusual bleeding, but only after major surgery or injury.

Other symptoms may include:

  • Joint pain from internal bleeding. Joints in your ankles, knees, hips and shoulders may ache, swell or feel hot to the touch.
  • Bleeding into your brain. People with severe hemophilia very rarely develop life-threatening bleeding into their brains. Brain bleeds may cause persistent headaches, double vision or make you feel very sleepy. If you have hemophilia and have these symptoms, get help right away.

What are hemophilia symptoms in babies and children?

Sometimes, babies assigned male at birth with hemophilia are diagnosed because they bleed more than usual after being circumcised. Other times, children develop symptoms a few months after they’re born. Common symptoms include:

  • Bleeding: Babies and toddlers may bleed from their mouths after minor injuries, like bumping their mouths on a toy.
  • Swollen lumps on their heads: Babies and toddlers who bump their heads often develop goose eggs — large round lumps on their heads.
  • Fussiness, irritability or refusal to crawl or walk: These symptoms may happen if babies and toddlers have internal bleeding into a muscle or joint. They may have areas on their bodies that look bruised and swollen, feel warm to your touch or make your child hurt when you gently touch the area.
  • Hematomas: A hematoma is a mass of congealed blood that gathers under babies’ or toddlers’ skin. Babies and toddlers may develop hematomas after receiving an injection.


What causes hemophilia?

Certain genes create clotting factors. In inherited hemophilia, the genes carrying instructions for making normal clotting factors mutate or change. The mutated genes may give instructions that end up making abnormal clotting factors or not enough clotting factors. That said, about 20% of all hemophilia cases are spontaneous, meaning someone has the disease even though there’s no family history of abnormal bleeding.

How do people inherit hemophilia?

Hemophilia A and B are both sex-linked disorders that are inherited in an X-linked recessive manner. Here’s how that happens:

  • Everyone receives one set of chromosomes from their biological mother and one set of chromosomes from their biological father. If you get an X chromosome from your mother and an X chromosome from your father, you are assigned female at birth. If you get an X chromosome from your mother and a Y chromosome from your father, you are assigned male at birth. In other words, a mother will always pass an X chromosome to her offspring. The father will determine the assigned sex at birth by providing either an X or a Y chromosome.
  • If a woman has an abnormal factor gene on one of their X chromosomes, they carry hemophilia but may not have symptoms. That’s because there’s a normal factor gene on their second X chromosome.
  • If a woman who carries an X chromosome with a defective gene for producing factor 8 (or factor 9) has a male child, that child has a 50% chance of inheriting the X chromosome that carries the abnormal factor gene.
  • If that same woman has a female child, that child has a 50% chance of inheriting the faulty chromosome and abnormal factor gene. That child likely wouldn’t have symptoms because they’ll also inherit a normal X chromosome from their father.
  • In other words, a woman who inherits a faulty X chromosome and abnormal factor gene will carry hemophilia. They may not have symptoms, but they can pass the condition on to their children. There’s a 50% chance that any children they have — boys or girls — will inherit hemophilia. Boys who do inherit hemophilia are more likely to have severe symptoms. That’s because they don’t get a healthy X chromosome from their father.
Do women ever develop hemophilia symptoms?

They can, but those symptoms tend to be mild. For example, a woman carrying the hemophilia gene may not have the normal clotting factors or not enough clotting factors. When that happens, they may have unusually heavy menstrual periods and they may bruise easily. They may bleed more after childbirth and they may develop joint problems if they have internal bleeding into their joints.

Diagnosis and Tests

How do healthcare providers diagnose hemophilia?

A healthcare provider will start by doing a complete history and physical examination. If you have hemophilia symptoms, the provider will ask about your family’s medical history. Providers may do the following tests:

  • Complete blood count (CBC): Providers use this test to measure and study blood cells.
  • Prothrombin time (PT) test: Providers use this test to see how quickly your blood clots.
  • Activated partial thromboplastin time test: This is another blood test to time blood clot formation.
  • Specific clotting factor test(s): This blood test show levels of specific clotting factor levels (such as factor 8 and factor 9).

What are clotting factor levels?

Clotting factors help control bleeding. Healthcare providers categorize hemophilia as being mild, moderate or severe based on the amount of clotting factors in your blood:

  • People who have 5% to 30% of the normal amount of clotting factors in their blood have mild hemophilia.
  • People with 1% to 5% of the normal level of clotting factors have moderate hemophilia.
  • People with less than 1% of the normal clotting factors have severe hemophilia.


Management and Treatment

How do healthcare providers treat hemophilia?

They treat hemophilia by boosting clotting factor levels or replacing missing clotting factors (replacement therapy).

In replacement therapy, you receive human plasma concentrates or lab-made (recombinant) clotting factors. In general, only people with severe hemophilia need regular replacement therapy. People with mild or moderate hemophilia who need surgery may receive replacement therapy. They may also receive antifibrinolytics, a medication that keeps blood clots from breaking down.

Blood factor concentrates are made from donated human blood that’s been treated and screened to reduce the risk of transmitting infectious diseases, such as hepatitis and HIV. People receive replacement factors via intravenous infusion (IV).

If you have severe hemophilia and frequent bleeding episodes, your healthcare provider may prescribe prophylactic factor infusions to prevent bleeding.

What are treatment complications?

Some people who have replacement therapy develop antibodies, called inhibitors, which attack the clotting factors that control bleeding. Healthcare providers use a technique called immune tolerance induction (ITI). ITI involves clotting factors given on a daily basis to bring down inhibitor levels. ITI may be a long-term treatment, and some people may need this treatment for months or years.


Can people prevent hemophilia?

No, they can’t. If you have hemophilia and have children, your healthcare provider may recommend genetic testing so you and your children know whether they might pass hemophilia on to their children.

Outlook / Prognosis

What can I expect if I have hemophilia?

If you have hemophilia, you’ll need medical treatment for the rest of your life. How much treatment you’ll need depends on your condition type, severity and if you develop inhibitors.

What is the lifespan expectancy for someone with hemophilia?

According to 2012 data from the World Federation of Hemophilia, the lifespan for men and people AMAB with hemophilia is about 10 years fewer than the lifespan for men/people AMAB without hemophilia. The federation also states that children diagnosed with and treated for hemophilia have a normal life expectancy.

But everyone is different. What’s true for one person with hemophilia may not be true for others. If you or your child has hemophilia, ask your provider what you can expect. They know your/your child’s situation, including overall health, and they’re your best resource for information.

Living With

How do I take care of myself?

People with hemophilia may need ongoing medical treatment to prevent bleeding. They may need to avoid certain activities and medications. But there are many things you can do to manage the impact hemophilia may have on the quality of your life.

Activities to avoid

Bumps, falls and hard knocks that other people shake off may be serious issues for people with hemophilia. They may need to avoid activities that increase their risk of being hit or falling down after being hit. Examples include:

  • Playing football, hockey or rugby.
  • Participating in boxing or wrestling.
  • Riding motorcycles.
  • Riding skateboards.

Participating in other sports such as soccer, basketball and baseball may increase your risk of injuries. Ask your healthcare provider what you can do, like using protective gear, so you can play these sports.

Medications to avoid

Pain medications like aspirin, ibuprofen and naproxen keep your blood from clotting well. You should also avoid anticoagulants such as heparin or warfarin.

Activities and actions to improve quality of life

There are many things you can do to limit the impact hemophilia may have on your quality of life:

  • Develop an exercise routine: You may worry about hurting yourself during exercise. Talk to your provider about ways to reduce the risk of bleeding while staying active.
  • Manage your stress: Hemophilia is a lifelong illness. It may take extra effort to balance your obligations to your family and work.
  • Have good dental hygiene: Brushing, flossing and regular visits to your dentist reduce the risk that you’ll need dental treatment that may cause bleeding. Be sure your dentist knows about your medical condition.
  • Aim for a weight that’s healthy for you: Managing your weight may help if you’re having trouble getting around because internal bleeding damaged your joints.
  • Educate those around you: If you have a severe form of hemophilia, you may have spontaneous bleeding that’s hard to control even if you’re taking medication. Make sure your family knows what to do if you have spontaneous bleeding. If your child has hemophilia, make sure care providers and school officials know what to do if your child has bleeding issues.

When should I see my healthcare provider?

Contact your healthcare provider if you notice changes in your body, like increased bleeding or bruising.

When should I go to the emergency room?

You should go to the emergency room if:

  • You have severe headaches or double vision. These symptoms may mean you have bleeding in your brain.
  • You have joint swelling and/or pain and you don’t have access to factor replacement medication.

What questions should I ask my healthcare provider?

If you or your child is diagnosed with hemophilia, you may want to ask your provider some of the following questions:

  • What type of hemophilia do I/does my child have?
  • What treatments do you recommend?
  • What are treatment side effects?
  • Will I/my child always need treatment?
  • What activities will I/my child need to avoid?
  • What medications will I/my child need to avoid?
  • What are things I can do to manage the impact this condition may have on my/my child’s life?

A note from Cleveland Clinic

Hemophilia is a rare, inherited blood disorder that changes people’s lives. People with hemophilia may need medical treatment for the rest of their lives. Parents of children with hemophilia may feel anxious about protecting them from accidental injuries. They may worry about helping their children learn to live with hemophilia. At this time, healthcare providers can’t cure hemophilia. They can provide treatment to prevent or reduce hemophilia symptoms. And they can make recommendations for steps people can take to limit hemophilia’s impact on daily life.

Medically Reviewed

Last reviewed on 11/14/2022.

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