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Hemophilia is a bleeding disorder caused by a lack of blood clotting factor. The disorder can be mild, moderate or severe, depending on the level of clotting factor. More than 15,000 people in the United States have hemophilia.

The condition is usually inherited from a parent with a genetic mutation. However, in about a third of patients, there is no family history of the disease and the disorder is caused by a new genetic mutation. Although most children with hemophilia have signs of bleeding during infancy or childhood, some people with mild hemophilia may not have symptoms until they're adults.

Types of hemophilia

The most common type of hemophilia, caused by a lack of clotting factor VIII, is called hemophilia A, or classic hemophilia. The second most common type is caused by a lack of clotting factor IX, and is called hemophilia B, also known as Christmas disease, named after Stephen Christmas, the first person diagnosed with the factor IX deficiency.

Hemophilia A and B occur almost always in males. A third, very rare type of hemophilia, sometimes called Hemophilia C, is caused by a lack of clotting factor XI, and occurs in both males and females.

Causes of hemophilia

Hemophilia A and B are caused by genetic mutations in the gene for factor VIII or factor IX. Mutations are abnormal changes that occur in a gene. The gene for factor VIII and factor IX is located on the X chromosome, making Hemophila A and B X-linked disorders. As such, one copy of the abnormal factor VIII or factor IX gene results in hemophilia in males, and a carrier state in females.

When there is a family history of hemophilia, the mother usually is a carrier and half of her sons and some of her male relatives will have hemophilia. If there is no family history of hemophilia, the disorder is due to a new mutation that occurred either in the affected individual or in the individual's mother, whose carrier state may have gone unnoticed.

Our approach to hemophilia

As a federally designated hemophilia treatment center, UCSF provides the full range of services – including diagnosis, treatment, counseling and education – to patients with all types of hemophilia.

We believe in treating the whole person. We emphasize listening to our patients and developing personalized care plans that address all the medical and emotional aspects of living with a bleeding disorder.

Awards & recognition

  • Among the top hospitals in the nation

  • CDC-2x

    Designated hemophilia treatment center (Centers for Disease Control and Prevention)

Signs & symptoms

The most common symptom of hemophilia is bleeding, particularly into the joints and muscles. When a person with hemophilia is injured, he does not bleed faster than a person without hemophilia, but it takes longer for bleeding to stop. Bleeding also may start again several days after an injury or surgery.

Small cuts or surface bruises usually are not a problem, but deeper injuries may result in bleeding episodes that can lead to permanent disability unless they are treated promptly.

Other symptoms of hemophilia include easy bruising, prolonged nosebleeds or vomiting of blood.

Symptoms and severity of hemophilia

Hemophilia may occur in mild, moderate and severe forms, based on both the patient's symptoms and the level or amount of clotting factor in the blood.

  • Mild hemophilia. The person has 6 percent to 49 percent of the normal factor level, and usually bleeds only after serious injury, trauma or surgery. The first episode of bleeding may not occur until adulthood.
  • Moderate hemophilia. The person has 1 percent to 5 percent of the normal factor level and has bleeding episodes after injuries, major trauma or surgery. He also may experience occasional bleeding without obvious cause, called spontaneous bleeding episodes.
  • Severe hemophilia. The person has less than 1 percent factor level and experiences bleeding following an injury or surgery, and may have frequent spontaneous bleeding episodes into the joints and muscles.

A person's severity of hemophilia does not change over time, because factor level is determined by genetics.


Accurate diagnosis is essential for the optimal management of hemophilia. Testing for hemophilia should be performed at a highly experienced specialized coagulation laboratory. Laboratories that do not frequently perform these specialized tests may not be able to accurately establish a diagnosis.

Most people with hemophilia are diagnosed at an early age. However, those with mild hemophilia may not be diagnosed until adulthood when they experience a bleeding episode due to trauma or surgery.

Hemophilia is diagnosed with blood tests to determine if clotting factors are missing or at low levels, and which ones are causing the problem. If you have a family history of hemophilia, it is important that your doctors know the clotting factor your relatives are missing. You will probably be missing the same one.

If you know you are a carrier of hemophilia, the testing for hemophilia in your newborn usually occurs soon after birth. These tests can be run on blood obtained from the umbilical cord or drawn from the newborn's vein. You may be advised to delay some procedures, such as circumcision, until after you learn whether your child has hemophilia.

Some families with a history of hemophilia may want to request prenatal testing, or testing before birth. This testing can be done early in pregnancy, allowing your family to make informed decisions and preparations. UCSF has genetic counselors who are available to help you with prenatal testing, if desired.

If you are pregnant and think you could be a carrier, or if you have a child diagnosed with hemophilia and are expecting another child, it is important to tell your obstetrician.

There are three ways to determine if you are a carrier:

  • Family tree. If you have a son with hemophilia and have another son, brother, father, uncle, cousin or grandfather with the disorder, then you are a carrier. No additional tests are needed.
  • Clotting factor. If the clotting factor level in your blood is below 50 percent of normal, you are probably a carrier and have mild hemophilia. If the clotting factor level is above 50 percent, you still may be a carrier, since other conditions can elevate the factor level. Other tests may be necessary.
  • DNA test. A DNA test can look for the mutation that caused hemophilia in your son or another relative, and compare it to your DNA.


Our health care team can help you decide which is the best treatment option for you. We rely on your input to help develop a plan of care that will keep you healthy, active and able to live successfully with the challenges of hemophilia.

The present goal of hemophilia therapy is to raise factor levels, decrease the frequency and severity of bleeding episodes and prevent complications of bleeding. Hemophilia treatment uses clotting factor concentrate, also called "factor," which is a dried powder form of the clotting factor. It is mixed with water to form a liquid before it is given.

Some clotting factor products, called plasma-derived factor products, are made from donated human blood plasma. Others, called recombinant factor products, are made in a laboratory.

Clotting factor concentrate is injected into your vein soon after you have had an injury or show signs of bleeding. When clotting factor is given, it immediately circulates in the blood so the body can use it to form a blood clot. Once the blood clot is established and the bleeding has stopped, the body begins to reabsorb the blood that has leaked into the tissues and joints.

If you do not receive prompt treatment, extra blood can pool in the joint or soft tissue and cause pain and swelling that takes longer to go away. Over time, repeated bleeding into a joint can lead to severe joint damage and arthritis. Early treatment will minimize the risk of joint damage.

If you have mild hemophilia, you may only need to be treated episodically, that is, each time you experience a bleeding episode. If your hemophilia is moderate or severe, your hemophilia may require more frequent treatment.

Home therapy

All factor treatments are infused or injected intravenously into a vein. At first, you will be treated at a hemophilia treatment center, your doctor's office or an emergency room. Later, you may be taught how to administer the factor at home.

Whether or not you are on home treatment, you should always have factor concentrate at home, since you may need to take it to the emergency room when you need a treatment. If the decision is made to infuse factor to treat your bleeding episode, the most important thing you can do is to administer it as soon as possible.

After you receive factor treatment for a joint bleed, rest, ice, compression and elevation (or "RICE") are required. You may also benefit from support devices, such as crutches following a bleed into the knee or ankle, or a sling following a bleed into a muscle or joint in the arm. Depending on the site of the bleed, you may have to limit activities for a few days after a bleed.

Over-the-counter medications

Acetaminophen is recommended as a safe pain reliever for people with hemophilia. Follow the directions carefully and be sure to take only the recommended amount of the medicine.

Never take any product with aspirin, or acetylsalicylic acid, in it. Aspirin can interfere with clotting. Many common household remedies, such as Alka-Seltzer, contain aspirin, so read labels very carefully before you take any medication.

Nonsteroidal anti-inflammatory drugs such as Advil, Aleve and Motrin, also may interfere with clotting; these should be used only if you have discussed their side effects with your doctor.

If you have any questions about what is or is not safe for you to take, talk to your doctor or hemophilia medical staff.

Experimental treatments

Research into such treatments as gene therapy and longer acting clotting factor concentrate is ongoing. The UCSF Hemophilia Treatment Center routinely participates in clinical trials involving new therapies.

UCSF Health medical specialists have reviewed this information. It is for educational purposes only and is not intended to replace the advice of your doctor or other health care provider. We encourage you to discuss any questions or concerns you may have with your provider.

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