What is hemophilia?
Hemophilia is an inherited condition in which blood isn’t able to clot normally.1 Essentially, one of your clotting factors is missing or the level of that specific factor is low.
The “factor” is a protein in your blood’s plasma that tells it to clot. Because there are several clotting factors in your blood’s plasma, each factor is given a Roman numeral. For example, for factor eight, we use VIII.1
There are two main types of hemophilia: hemophilia A or classic hemophilia (which is a Factor VIII deficiency) and hemophilia B or Christmas Disease (a Factor IX deficiency). Hemophilia A is about four times more common than hemophilia B.2
The clotting process
Our blood clots for a single reason: to prevent leakage of blood whenever there is a tear in the wall of a blood vessel. When there’s less clotting factor, the cellular chain of events that happens in order for your blood to clot does not work effectively.1
Hemophilia severity
Severity in hemophilia is usually classified by the amount of clotting factor. For example, severe hemophilia is when you have less than 1% of the normal clotting factor level. This results in immediate bleeding after injury and frequent spontaneous bleeding, often into joints and muscles.3
Moderate hemophilia patients have 1%-5% of the normal amount of clotting factor, which makes for some spontaneous bleeding and bleeding with trauma or surgery.3
Mild hemophilia, when about 6-49% of the normal amount of clotting factor is present, commonly results in bleeding with major trauma or surgery.3
Genetics
While most cases are inherited, we know that the hemophilia gene is found on the X chromosome. Women have two X chromosomes and men have only one. So, in almost all cases, if a woman carries an altered hemophilia gene on one of her X’s, the other one will make up for it, which is why hemophilia mostly occurs with men.3
To see how the gene is passed along between mothers and fathers to their children, see these diagrams.4 To find out if either you or your partner are carriers for the hemophilia gene, look into genetic counseling. It’s a wide range of tests for diagnostic and carrier detection. To find information on genetic counseling ask your hemophilia treatment center (or HTC).
Impact of bleeds
Over the long term, bleeds can lead to permanent damage. Joint bleeds can cause a decrease in range of motion, chronic pain and decreased muscle mass. Muscle bleeds can make for weak, scarred and shorter muscles. This could mean permanent damage to joints, muscles and nerves, affecting the way you sit, stand and walk.2
If you experience bleeds in the head, eye, neck or throat, chest, abdomen or stomach, and kidney or bladder, you must seek medical treatment ASAP. Also, seek treatment immediately if you feel any tingling or numbness in a muscle or a joint.6
Get connected
Interested in attending a live or virtual event? Want to get in touch with other members of the hemophilia community?
Meet Your Bayer Rep- World Federation of Hemophilia. Hemophilia in pictures. https://www1.wfh.org/publications/files/pdf-1311.pdf. Accessed January 30, 2024.
- World Federation of Hemophilia. Guidelines for the Management of Hemophilia. 2nd ed. 2012. https://www1.wfh.org/publications/files/pdf-1863.pdf. Accessed January 30, 2024.
- National Bleeding Disorder Foundation. Hemophilia A. https://www.hemophilia.org/Bleeding-Disorders/Types-of-Bleeding-Disorders/Hemophilia-A. Accessed January 30, 2024.
- World Federation of Hemophilia. Symptomatic Carriers of Hemophilia. 2008.
- Simpson, Mindy L., and Leonard A. Valentino. “Management of Joint Bleeding in Hemophilia.” Expert Review of Hematology, vol. 5, no. 4, Aug. 2012, pp. 459–68. DOI.org (Crossref), https://doi.org/10.1586/ehm.12.27. Accessed April 25, 2024.
- National Bleeding Disorder Foundation. Types of bleeds. http://www.hemophilia.org/Bleeding-Disorders/Types-of-Bleeds. Accessed January 30, 2024.
