Hemophilia is a rare disorder in which the blood doesn't clot in the typical way because it doesn't have enough blood-clotting proteins (clotting factors). If you have hemophilia, you might bleed for a longer time after an injury than you would if your blood clotted properly.

Small cuts usually aren't much of a problem. If you have a severe form of the condition, the main concern is bleeding inside your body, especially in your knees, ankles and elbows. Internal bleeding can damage your organs and tissues and be life-threatening.

Hemophilia is almost always a genetic disorder. Treatment includes regular replacement of the specific clotting factor that is reduced. Newer therapies that don't contain clotting factors also are being used.


Signs and symptoms of hemophilia vary, depending on your level of clotting factors. If your clotting-factor level is mildly reduced, you might bleed only after surgery or trauma. If your deficiency is severe, you can bleed easily for seemingly no reason.

Signs and symptoms of spontaneous bleeding include:

  • Unexplained and excessive bleeding from cuts or injuries, or after surgery or dental work
  • Many large or deep bruises
  • Unusual bleeding after vaccinations
  • Pain, swelling or tightness in your joints
  • Blood in your urine or stool
  • Nosebleeds without a known cause
  • In infants, unexplained irritability

Bleeding into the brain

A simple bump on the head can cause bleeding into the brain for some people who have severe hemophilia. This rarely happens, but it's one of the most serious complications that can occur. Signs and symptoms include:

  • Painful, prolonged headache
  • Repeated vomiting
  • Sleepiness or lethargy
  • Double vision
  • Sudden weakness or clumsiness
  • Convulsions or seizures


When to see a doctor

Seek emergency care if you or your child has:

  • Signs or symptoms of bleeding into the brain
  • An injury in which the bleeding won't stop
  • Swollen joints that are hot to the touch and painful to bend

When a person bleeds, the body typically pools blood cells together to form a clot to stop the bleeding. Clotting factors are proteins in the blood that work with cells known as platelets to form clots. Hemophilia occurs when a clotting factor is missing or levels of the clotting factor are low.

Congenital hemophilia

Hemophilia is usually inherited, meaning a person is born with the disorder (congenital). Congenital hemophilia is classified by the type of clotting factor that's low.

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

Acquired hemophilia

Some people develop hemophilia with no family history of the disorder. This is called acquired hemophilia.

Acquired hemophilia is a variety of the condition that occurs when a person's immune system attacks clotting factor 8 or 9 in the blood. It can be associated with:

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

Hemophilia inheritance

In the most common types of hemophilia, the faulty gene is located on the X chromosome. Everyone has two sex chromosomes, one from each parent. Females inherit an X chromosome from the mother and an X chromosome from the father. Males inherit an X chromosome from the mother and a Y chromosome from the father.

This means that hemophilia almost always occurs in boys and is passed from mother to son through one of the mother's genes. Most women with the defective gene are carriers who have no signs or symptoms of hemophilia. But some carriers can have bleeding symptoms if their clotting factors are moderately decreased.

Risk factors

The biggest risk factor for hemophilia is to have family members who also have the disorder. Males are much more likely to have hemophilia than are females.


Complications of hemophilia can include:

  • Deep internal bleeding. Bleeding that occurs in deep muscle can cause the limbs to swell. The swelling can press on nerves and lead to numbness or pain. Depending on where the bleeding occurs, it could be life-threatening.
  • Bleeding into the throat or neck. This can affect a person's ability to breathe.
  • Damage to joints. Internal bleeding can put pressure on the joints, causing severe pain. Left untreated, frequent internal bleeding can cause arthritis or destruction of the joint.
  • Infection. If the clotting factors used to treat hemophilia come from human blood, there's an increased risk of viral infections such as hepatitis C. Because of donor screening techniques, the risk is low.
  • Adverse reaction to clotting factor treatment. In some people with severe hemophilia, the immune system has a negative reaction to the clotting factors used to treat bleeding. When this happens, the immune system develops proteins that keep the clotting factors from working, making treatment less effective.


Severe cases of hemophilia usually are diagnosed within the first year of life. Mild forms might not be apparent until adulthood. Some people learn they have hemophilia after they bleed excessively during a surgical procedure.

Clotting-factor tests can reveal a clotting-factor deficiency and determine how severe the hemophilia is.

For people with a family history of hemophilia, genetic testing might be used to identify carriers to make informed decisions about becoming pregnant.

It's also possible to determine during pregnancy if the fetus is affected by hemophilia. However, the testing poses some risks to the fetus. Discuss the benefits and risks of testing with your doctor.


The main treatment for severe hemophilia involves replacing the clotting factor you need through a tube in a vein.

This replacement therapy can be given to treat a bleeding episode in progress. It can also be given on a regular schedule at home to help prevent bleeding episodes. Some people receive continuous replacement therapy.

Replacement clotting factor can be made from donated blood. Similar products, called recombinant clotting factors, are made in a laboratory, not from human blood.

Other therapies include:

  • Desmopressin. In some forms of mild hemophilia, this hormone can stimulate the body to release more clotting factor. It can be injected slowly into a vein or used as a nasal spray.
  • Emicizumab (Hemlibra). This is a newer drug that doesn't include clotting factors. This drug can help prevent bleeding episodes in people with hemophilia A.
  • Clot-preserving medications. Also known as anti-fibrinolytics, these medications help prevent clots from breaking down.
  • Fibrin sealants. These can be applied directly to wound sites to promote clotting and healing. Fibrin sealants are especially useful for dental work.
  • Physical therapy. It can ease signs and symptoms if internal bleeding has damaged your joints. Severe damage might require surgery.
  • First aid for minor cuts. Using pressure and a bandage will generally take care of the bleeding. For small areas of bleeding beneath the skin, use an ice pack. Ice pops can be used to slow down minor bleeding in the mouth.

Lifestyle and home remedies

To avoid excessive bleeding and protect your joints:

  • Exercise regularly. Activities such as swimming, bicycle riding and walking can build muscles while protecting joints. Contact sports — such as football, hockey or wrestling — are not safe for people with hemophilia.
  • Avoid certain pain medications. Drugs that can make bleeding worse include aspirin and ibuprofen (Advil, Motrin IB, others). Instead, use acetaminophen (Tylenol, others), which is a safer alternative for mild pain relief.
  • Avoid blood-thinning medications. Medications that prevent blood from clotting include heparin, warfarin (Jantoven), clopidogrel (Plavix), prasugrel (Effient), ticagrelor (Brilinta), rivaroxaban (Xarelto), apixaban (Eliquis), edoxaban (Savaysa) and dabigatran (Pradaxa).
  • Practice good dental hygiene. The goal is to prevent tooth and gum disease, which can lead to excessive bleeding.
  • Get vaccinations. People with hemophilia should receive recommended vaccinations at the appropriate ages, as well as hepatitis A and B. Requesting use of the smallest gauge needle and having pressure or ice applied for 3 to 5 minutes after the injection can reduce the risk of bleeding.
  • Protect your child from injuries that could cause bleeding. Kneepads, elbow pads, helmets and safety belts all help prevent injuries from falls and other accidents. Keep your home free of furniture with sharp corners.

Coping and support

To help you and your child cope with hemophilia:

  • Get a medical alert bracelet. This lets medical personnel know that you or your child has hemophilia, and the type of clotting factor that's best in case of an emergency.
  • Talk with a counselor. Striking the right balance between keeping your child safe and encouraging as much activity as possible can be tricky. A social worker or therapist with knowledge of hemophilia can help identify the least amount of limitations your child needs.
  • Let people know. Be sure to tell anyone who will be taking care of your child — babysitters, child care workers, relatives, friends and teachers — about your child's condition. If your child plays noncontact sports, be sure to tell coaches, too.

Preparing for an appointment

If you or your child has signs or symptoms of hemophilia, you might be referred to a doctor who specializes in blood disorders (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 medications, vitamins and supplements, including doses

Questions to ask your doctor

  • What's the most likely cause of these signs and symptoms?
  • What tests are needed? Do they require special preparation?
  • What treatment do you recommend?
  • What activity restrictions are recommended?
  • What is the risk of long-term complications?
  • Do you recommend that our family meet with a genetic counselor?

Don't hesitate to ask other questions, as well.

What to expect from your doctor

Your doctor is likely to ask you a number of questions, including:

  • Have you noticed any unusual or heavy bleeding, such as nosebleeds or prolonged bleeding from a cut or vaccination?
  • If you or your child has had surgery, did the surgeon mention excessive bleeding?
  • Are you or your child prone to developing large, deep bruises?
  • Do you or your child have pain or warmth around joints?

Content From Mayo Clinic Updated: 08/28/2023
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