Hemophilia

Find out how this blood-clotting condition that's passed through families can cause life-threatening bleeding and what to do about it.

Update Date: 12.05.2026

Overview
Symptoms
Causes
Risk factors
Complications
Diagnosis
Treatment
Lifestyle and home remedies
Coping and support
Preparing for an appointment

Overview

Hemophilia is a rare condition in which the blood doesn't clot well. That's because it doesn't have enough blood-clotting proteins, called clotting factors. People with hemophilia might bleed longer after an injury than they would if the blood clotted as it should.

Small cuts aren't often much of a problem. For people with a serious form of hemophilia, the main concern is bleeding inside the body. Internal bleeding can damage organs and tissues and be life-threatening.

Gene changes that are passed through families, called inherited changes, are almost always the cause of hemophilia. Treatment includes regular replacement of the specific clotting factor that is low. There are newer therapies that don't have clotting factors, as well.

Symptoms

Symptoms of hemophilia vary, depending on the level of clotting factors. People with a slightly low clotting-factor level might bleed only after surgery or injury. People with a low amount of clotting factor may bleed easily for what seems like no reason, called spontaneous bleeding.

People with serious hemophilia often have symptoms in the first two years of life. For instance, an infant with severe hemophilia may first bleed too much during a heel stick to draw blood for newborn screening tests. People with milder hemophilia might not know they have the condition until later in life, maybe after injury or surgery.

Symptoms of hemophilia include:

  • A lot of bleeding from cuts or injuries, or after surgery or dental work.
  • Many large or deep bruises.
  • Bleeding more than is typical after vaccinations.
  • Hot, swollen and painful joints. Bleeding is common in the knees, ankles and elbows.
  • Blood in urine or stool.
  • Nosebleeds with no known cause.
  • In infants, being cranky for no known reason.

Bleeding into the brain

A simple bump on the head can cause bleeding into the brain for some people who have serious hemophilia. This is rare, but it's one of the most serious complications of the condition. Symptoms include:

  • Having a painful, long-lasting headache.
  • Repeated vomiting.
  • Feeling sleepy or sluggish.
  • Having convulsions or seizures.

Causes

When to see a doctor

Seek emergency care if you or your child has:

  • Symptoms of bleeding into the brain.
  • Bleeding that won't stop after an injury.
  • Swollen joints that feel hot and are painful.

The cause of hemophilia is a missing or low level of a clotting factor. Clotting factors are proteins in the blood that work with cells called platelets to form clots. Most often, when people bleed, blood cells pool together to form a clot to stop the bleeding. A missing or low clotting factor keeps blood from clotting well in people with hemophilia.

Congenital hemophilia

Hemophilia is most often inherited, meaning a person is born with the condition. This is called congenital. Congenital hemophilia is classified by the type of clotting factor that's low.

The most common type of congenital hemophilia is hemophilia A, linked with a low level of factor 8. The next most common type is hemophilia B, linked with a low level of factor 9.

Acquired hemophilia

Some people get hemophilia with no family history of the condition. This is called acquired hemophilia.

Acquired hemophilia happens when a person's immune system attacks clotting factor 8 or 9 in the blood. It can be linked with:

  • Pregnancy.
  • Autoimmune conditions.
  • Cancer.
  • Multiple sclerosis.
  • Drug reactions.

Hemophilia inheritance

In the most common types of hemophilia, the changed gene is on the X chromosome. Everyone has two sex chromosomes, one from each parent. People assigned female at birth get an X chromosome from the mother and an X chromosome from the father. People assigned male at birth get an X chromosome from the mother and a Y chromosome from the father.

This means that most people who get hemophilia are people assigned male at birth. The condition passes from mother to son through one of the mother's genes.

Most people assigned female at birth who have the changed gene are carriers. They tend to have no hemophilia symptoms. But some carriers can have bleeding symptoms if their clotting factors are lowered slightly.

Risk factors

The biggest risk factor for hemophilia is to have family members who also have the condition. People assigned male at birth are much more likely to have hemophilia than are people assigned female at birth.

Complications

Complications of hemophilia can include:

  • Deep internal bleeding. Bleeding that happens in deep muscle can cause the arms and legs to swell. The swelling can press on nerves and lead to numbness or pain. Depending on where the bleeding happens, it may be life-threatening.
  • Bleeding into the throat or neck. This can cause trouble with breathing.
  • Damage to joints. Internal bleeding can put pressure on the joints, causing pain. Untreated, internal bleeding that happens often can cause arthritis or destroy the joint.
  • Infection. If the clotting factors that treat hemophilia come from human blood, there's a risk of viral infections such as hepatitis C. Because of donor blood screening, the risk is low.
  • Reaction to clotting factor treatment. In some people with hemophilia, the immune system reacts to the clotting factors that treat bleeding. When this happens, the immune system makes proteins that keep the clotting factors from working. This may keep treatment from working well.

Diagnosis

Most people with serious hemophilia get a diagnosis within the first year of life. People with mild forms may not know they have the condition until they're adults. Some people learn they have hemophilia after bleeding more than expected during a surgical procedure.

Tests

Tests can help diagnose hemophilia. They may include:

  • Screening tests. These are blood tests that can show how well the blood clots.
  • Clotting-factor tests. These blood tests can show a lack of a clotting factor. The tests also can show the type of hemophilia and whether it's mild, moderate or severe.
  • Genetic tests. People with a family history of hemophilia might have genetic testing. This can show who is a carrier and help with deciding about becoming pregnant.
  • Prenatal tests. It's possible to learn during pregnancy whether hemophilia affects the unborn baby. But the testing poses some risks to the fetus. Talk with your healthcare professional about the pros and cons of prenatal testing.

Treatment

The main treatment for severe hemophilia involves replacing the missing or low clotting factor through a tube in a vein.

This therapy can treat a bleeding episode as it's happening. Some people get the treatment on a regular schedule at home to help prevent bleeding episodes. Some people get ongoing replacement therapy.

Replacement clotting factor can come from donated blood. Other products, called recombinant clotting factors, come from a laboratory, not from human blood.

Other therapies include:

  • Desmopressin. In some forms of mild hemophilia, this hormone can trigger the body to release more clotting factor. A healthcare professional may put it slowly into a vein. Or some people use it as a nasal spray.
  • Emicizumab (Hemlibra). This is a newer medicine that doesn't have clotting factors. It can help prevent bleeding in people with hemophilia A.
  • Concizumab (Alhemo) and marstacimab (Hympavzi). These newer medicines help prevent bleeding in both hemophilia A and B.
  • Clot-preserving medicines. Also called antifibrinolytics, these medicines help keep clots from breaking down. These include medicines such as aminocaproic acid (Amicar) and tranexamic acid (Lysteda). Taken by mouth, these medicines can help blood to clot and wounds to heal. These medicines are useful for surgery and dental work.
  • Fibrin sealants. A medicine called thrombin that goes on the skin may help with bleeding from surgery and dental work.
  • Gene therapy. The U.S. Food and Drug Administration has approved valoctocogene roxaparvovec (Roctavian) for treatment of serious hemophilia A and etranacogene dezaparvovec-drlb (Hemgenix) for hemophilia B. These treatments go into a vein to carry the missing blood-clotting factor into the body. These one-time treatments cause the body to make more of the missing blood clotting factor.
  • Physical therapy. It can ease symptoms if internal bleeding has damaged the joints. More serious damage might need surgery.

Lifestyle and home remedies

To manage bleeding and to protect your joints:

  • Exercise regularly. Activities such as swimming, bike riding and walking can build muscles while protecting joints. Contact sports, such as football, hockey or wrestling, aren't safe for people with hemophilia.
  • Don't take certain pain medicines. Medicines that can make bleeding worse include aspirin and ibuprofen (Advil, Motrin IB, others). Instead, use acetaminophen (Tylenol, others) for mild pain relief.
  • Don't take blood-thinning medicines. Medicines that keep blood from clotting include heparin, warfarin (Jantoven), clopidogrel (Plavix), prasugrel (Effient), ticagrelor (Brilinta), rivaroxaban (Xarelto), apixaban (Eliquis), edoxaban (Savaysa) and dabigatran (Pradaxa).
  • Take care of your teeth. The goal is to prevent tooth and gum disease, which can lead to bleeding.
  • Get vaccinations. People with hemophilia need to get vaccinations at the right ages. They also should get hepatitis A and B vaccinations. Ask for the smallest gauge needle. Put pressure or ice on the site for 3 to 5 minutes after the shot to lower the risk of bleeding.
  • Protect children from injuries that could cause bleeding. Knee pads, elbow pads, helmets and safety belts all help prevent injuries from falls and other accidents. Make sure the furniture in your home doesn't have sharp corners.
  • Treat minor wounds. Using pressure and a bandage most often stops bleeding of a minor cut. For small areas of bleeding under the skin, use an ice pack. Suck an ice pop to slow minor bleeding in the mouth.

Coping and support

To help you and your child cope with hemophilia:

  • Get a medical alert bracelet. This lets medical professionals know that you or your child has hemophilia. The bracelet also has the type of clotting factor that's best in case you need it.
  • Talk with a counselor. Finding the right balance between keeping your child safe but also active can be tricky. A social worker or therapist who knows about hemophilia can help show the limits you need to place on your child.
  • Let people know. Be sure to tell anyone who takes care of your child about your child's condition. This includes babysitters, child care workers, relatives, friends and teachers. If your child plays noncontact sports, tell coaches too.

Preparing for an appointment

If you or your child has symptoms of hemophilia, your main healthcare professional may send you to a doctor who specializes in blood disorders, called a hematologist.

What you can do

Make a list of:

  • Symptoms and when they began
  • Key medical information, including other conditions, and a family history of bleeding disorders.
  • All medicines, vitamins and supplements, including dosages.

Questions to ask your healthcare professional

  • What's the most likely cause of these symptoms?
  • What tests diagnose this condition?
  • What treatment do you suggest?
  • What activity restrictions do you suggest?
  • What is the risk of long-term complications?
  • Do you think that meeting with a genetic counselor can help our family?

Be sure to ask all the questions you have.

What to expect from your doctor

Questions your healthcare professional may ask include:

  • Have you seen any heavy bleeding, such as nosebleeds or bleeding a long time from a cut or vaccination?
  • If you or your child has had surgery, did the surgeon talk about a lot of bleeding?
  • Do you or your child get large, deep bruises?
  • Do you or your child have pain or warmth around joints?

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