Hemophilia is an inherited bleeding disorder in which the blood does not clot properly. Blood contains many proteins called clotting factors that help to stop bleeding. These factors are numbered from 1 through 13, using roman numerals (such as I, IV, or X). People with hemophilia have either a low level of these clotting factors or none at all. The lower the level, the more serious the hemophilia, and problems such as bleeding without obvious cause or bleeding following injuries or surgery is more likely.
Hemophilia can result in:
- Joint swelling that can lead to damage or swelling in the muscle
- Bleeding in the head and sometimes in the brain leading to brain damage
- Damage to other organs in the body
- Pain as a result of bleeding in various organs
- Death can occur if the bleeding cannot be stopped or if it occurs in a vital organ such as the brain.
"Do the 5"
Tips for Healthy Living
- Get an annual comprehensive checkup at a hemophilia treatment center.
- Get vaccinated—Hepatitis A and B are preventable.
- Treat bleeds early and adequately.
- Exercise and maintain a healthy weight to protect your joints.
- Get tested regularly for blood-borne infections.
There are several different types of hemophilia. The following two are the most common:
- Hemophilia A (Classic Hemophilia)
This type is caused by a lack or decrease of clotting factor VIII (8).
- Hemophilia B (Christmas Disease)
This type is caused by a lack or decrease of clotting factor IX (9).
Signs and Symptoms
The major signs of hemophilia are bleeding that is unusually heavy or lasts a long time, or bleeding and bruising that happens without obvious cause. The amount of bleeding depends on the type and severity of hemophilia and how serious it is.
Other common signs include:
- Bleeding into the joints. This can cause swelling and pain or tightness in the joints; it often affects the knees, elbows, and ankles.
- Bleeding into the skin (which is bruising) or muscle and soft tissue causing a build-up of blood in the area (called a hematoma).
- Bleeding of the mouth and gums, and bleeding that is hard to stop after losing a tooth.
- Bleeding after circumcision (surgery performed on male babies to remove the hood of skin, called the foreskin, covering the head of the penis).
- Bleeding after having shots.
- Bleeding in the head of an infant after a difficult delivery.
- Blood in the urine or stool.
- Frequent and hard-to-stop nosebleeds.
Hemophilia is caused by a problem in one of the genes that tells the body to make the clotting factor proteins needed to form a blood clot. These genes are located on the X chromosome. All males have one X and one Y chromosome (XY) and all females have two X chromosomes (XX).
Males who inherit an affected X chromosome have hemophilia. Rarely, a condition called "female hemophilia" occurs. In such cases both X chromosomes are affected or one is missing or inactive. In these women, bleeding symptoms may be similar to males with hemophilia.
A female who inherits one affected X chromosome becomes a "carrier" of hemophilia. A female who is a carrier sometimes can have symptoms of hemophilia. In addition, she can pass the affected gene on to her children. Learn more about the inheritance pattern for hemophilia.
Even though hemophilia is genetic, it does occur among families with no prior history. About one-third of newly diagnosed babies have no family history of hemophilia. These cases are thought to be due to a change to the gene's instructions for making the clotting factor protein, called a "mutation." This change or mutation can prevent the clotting protein from working properly or to be missing altogether.
Who is Affected
Hemophilia is a common inherited bleeding disorder. Hemophilia occurs among about 1 of every 5,000 male births. Currently, about 20,000 males in the United States have the disorder. Hemophilia A is about four times as common as hemophilia B, and about half of those affected have the severe form. Hemophilia affects people from all racial and ethnic groups.
Many people who have or have had family members with hemophilia will ask that their baby boys get tested soon after birth.
About one-third of babies who are diagnosed with hemophilia have no other family members with the disorder. A doctor might check for hemophilia if a newborn is showing certain signs of hemophilia.
Diagnosis includes screening tests and clotting factor tests. Screening tests are blood tests that show if the blood is clotting properly. Clotting factor tests, also called factor assays, are required to diagnose a bleeding disorder. This blood test shows the type of hemophilia and the severity.
The best way to treat hemophilia is to replace the missing blood clotting factor so that the blood can clot properly. This is done by injecting commercially prepared clotting factor concentrates into a person’s vein.
Hemophilia is a complex disorder. Good quality medical care from doctors and nurses who know a lot about the disorder can help prevent some serious problems. Often the best choice is a comprehensive Hemophilia Treatment Center (HTC). An HTC provides care to address all issues related to the disorder, as well as education.
Learn more about treatment »
About 10 – 15 percent of people with hemophilia develop an antibody (called an inhibitor) that inhibits the action of the clotting factors used to treat bleeding. Treatment of bleeding becomes extremely difficult, and the cost of their care can skyrocket because more clotting factor or a different type of clotting factor is needed. Patients with inhibitors often experience increased joint disease and other complications from bleeding that result in a reduced quality of life.
- Centers for Disease Control and Prevention
National Center on Birth Defects and Developmental Disabilities
Division of Blood Disorders
1600 Clifton Road
Atlanta, GA 30333
TTY: (888) 232-6348
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