Hemophilia

Bleeding disorders are a group of disorders that share the inability to form a proper blood clot, leading to continuous bleeding if not treated. When platelets and clotting proteins that are parts of a person’s blood are missing or not working properly, then the person is unable to make a proper blood clot. The clotting proteins found in the blood are also known as clotting factors.

Hemophilia is the most well-known bleeding disorder and is caused when there is a lack or decrease of clotting factor VIII (8) or clotting factor IX (9). There are two main types of hemophilia. Hemophilia A happens if there is a problem with clotting factor VIII (8) and hemophilia B happens if there is a problem with clotting factor IX (9). 

This section about hemophilia includes the following:

What is Hemophilia?

Who Has Hemophilia?

Diagnosing Hemophilia

What is Hemophilia?

Hemophilia is an inherited bleeding disorder where the blood does not clot well. Your blood contains many proteins, called clotting factors, that help stop bleeding. If you have hemophilia, you have a gene with a mutation. The mutated gene in your body means the clotting factor protein needed to make a clot might be missing or not working properly. There are 13 clotting factors. These clotting factors are numbered from 1 through 13,using roman numbers like I or X.

People with hemophilia have a low level of factor VIII (hemophilia A), factor IX (hemophilia B), or none at all. The lower the level, the more severe the case of hemophilia. Lower levels of factor in your body make prolonged bleeding, or bleeding without a known cause, more likely. You may bleed inside your body, for example in the joints and muscles. Bleeds can also happen outside your body from minor cuts, dental or medical procedures, or injuries.

There are two different types of hemophilia:

• Hemophilia A: Occurs when there is a lack or decrease of clotting factor VIII (8).  Each year, about 400 babies are born with hemophilia A.² For men with bleeding disorders, hemophilia A is almost four times more common than hemophilia B.3 Women can also have hemophilia A. 

• Hemophilia B (also called Christmas disease): Occurs when there is a lack or decrease of clotting factor IX (9). There are 3.7 cases of hemophilia B for every 100,000 men in the United States.⁴ Women can also have hemophilia B. 

Who Has Hemophilia?

Currently, there are about 30,000 – 33,000 people living with hemophilia in the United States. These numbers do not include women with hemophilia, as research data among women with blood or bleeding disorders is still lacking.  Although men make up most cases of hemophilia, it is important to know that women can have hemophilia, too.  

Most people with hemophilia are diagnosed early in life. Children in the United States with mild hemophilia are often diagnosed at 36 months of age. Hemophilia affects all races and ethnic groups. One third of people with hemophilia are diagnosed without a previous family history of the disorder.

Diagnosing Hemophilia

Hemophilia is often an inherited disorder, and the gene that causes the disorder is passed from parents to children. For some people with hemophilia, the disorder is not inherited but caused by spontaneous genetic mutation. Many people with family members with hemophilia will ask for their infants to be tested soon after birth. If you do not have a history of hemophilia in your family, you may notice lots of bruising or find it takes longer for your body to stop bleeding.  

If you want more information about how hemophilia is inherited, please go to Genetics of Bleeding Disorders. 

Screenings and clotting factor tests, both of which are blood tests, may be used to diagnose hemophilia. Screening tests show if your blood is clotting well. Clotting factor tests, called factor assays, are used to confirm a diagnosis of a bleeding disorder. Factor assays are also used to identify the type of hemophilia and the severity level. With this information, a health care provider can create the best treatment and care plan for you. If you have questions about diagnosing hemophilia, the best place to go is a Hemophilia Treatment Center (HTC). An HTC is a specialized center that provides comprehensive care to people with bleeding disorders.  

If you want more information about where to find a Hemophilia Treatment Center, please go to the CDC HTC Search Directory. 

If you want more information about testing, especially for women, girls, and those who had or have the potential to menstruate (WGPPM), please go to What Women and Girls Should Know About Getting Tested for Bleeding Symptoms. 

Diagnosing Bleeding Disorders for WGPPM

For women, girls, and those who had or have the potential to menstruate (WGPPM), it may take years to be diagnosed with a bleeding disorder. Many women and girls are not tested before puberty, as heavy periods are a symptom of a bleeding disorder. Other symptoms may include bruising easily, frequent nosebleeds that last longer than 10 minutes, and bleeding from cuts or injuries that last longer than 10 minutes. If you have these symptoms, it is important to talk with a health care provider or go to a Hemophilia Treatment Center (HTC).  Many health care providers may be unfamiliar with the signs and symptoms of bleeding disorders, delaying diagnosis, treatment, and care. 

If you want more information about how to help providers understand bleeding disorders in women, girls, and those who have or had the potential to menstruate, please go to Don’t Miss the Signs. 

NBDF, in partnership with the CDC, created the Better You Know campaign to spread the word about bleeding disorders to undiagnosed women and health care providers.  On Betteryouknow.org there is a risk assessment tool that will let you know if you are at risk for a bleeding disorder, information and educational resources for health care providers, and ways to spread the word on social media. There are also tools and resources to help you advocate for your needs and take steps towards a diagnosis.