Hemophilia is a group of bleeding disorders. It is caused by low amounts of specific clotting factors. These factors help to stop bleeding.

The most common types of hemophilia are:

  • Hemophilia A (classic hemophilia)—accounts for 80% of all hemophilia (1 in 5,000 males), caused by too little factor VIII
  • Hemophilia B (Christmas disease)—occurs in 1 in 25,000 males, caused by too little factor IX


Hemophilia is caused by a faulty gene inherited from one or both parent. It is called an inherited sex-linked recessive gene. The gene is located on the X chromosome.

Females carry two copies of the X chromosome. If the faulty gene is only on one X, the normal gene on the second X will take over. As a result, they will not get the disease. Instead they are carriers of the gene. The risk for their male offspring to inherit the gene is 1 in 2 or 50%. The chance that their female offspring will inherit the gene is also 50%. These offspring will be carriers like their mothers.

It is possible for a female to have hemophilia. For this to happen she must inherit the faulty gene from both her mother and her father.

Males carry only one X chromosome. If they get the faulty gene the disease will develop.

Genetic Outcome Possibilities

Fetus Chromosomes
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Risk Factors

Factors that increase your chance of hemophilia include:

  • Family members with hemophilia
  • Family history of bleeding disorders
  • Sex: male


The severity of symptoms can vary. Severe forms become apparent early on. Bleeding is the main symptom. It may be noticed if an infant is circumcised. Additional bleeding problems appear when the infant becomes mobile.

Bleeding can be caused by an injury. It can produce excessive bruising after a minor trauma]]> or cut. It can also cause bleeding after extraction of teeth. Bleeding into joints is a common sign. This is called hemarthrosis. Intestinal bleeding may produce bloody stools. If it occurs in the small intestine it will cause black, tarry stools.

Mild cases may go unnoticed until later in life. Then they occur in response to surgery or trauma.

Symptoms for Hemophilia A and B may include:

  • Hot, swollen, sore, stiff, and/or deformed joints
  • Bleeding into muscles
  • Bleeding into the intestinal tract
  • Bloody stools
  • Bloody urine
  • Difficulty stopping bleeding after minor cuts or bumps
  • Heavy bleeding even after simple surgical or dental procedures

Symptoms for Hemophilia B may include:



Coagulation studies look at the ability of the blood to clot. These studies involve many tests. They are done if the person tested is the first one in the family with the disorder. Once identified, other family members will need less testing for a diagnosis.

The doctor will ask about your symptoms and medical history. A physical exam will be done.

Tests may include:

  • Tests of bleeding time
  • Blood tests to measure the amounts of clotting factors present


Treatment includes:

Blood Factor Concentrate

You'll be tested often to monitor your factor levels. When your factor levels drop too low, you'll be given a dose. Blood factor concentrate may be given through an IV.

People with hemophilia and their families can be taught to administer blood factor concentrate at home at the first signs of bleeding. This can help prevent a crisis. People with severe forms of the disease may need regular infusions.

Some patients develop an inhibitor to a particular factor. This may require treatment with other clotting factors.


The hepatitis B vaccine]]> is important. There is an increased risk of exposure to hepatitis with frequent infusions of blood products.

Cryoprecipitate or ]]>Desmopressin]]> (DDAVP)

Mild hemophilia may be treated with infusion of these medications. They cause the release of blood factor concentrate. The factor is stored within the body on the lining of blood vessels.



People who have hemophilia should avoid situations that might cause bleeding. They should be careful about dental care so they won't need to have teeth extracted. People who have hemophilia should also avoid certain drugs that can aggravate bleeding problems:

Genetic counselors can make a detailed family history. They will discuss risks and available testing options.