
Get to know hemophilia
The science behind clotting factors
Now that you know what hemophilia is, let’s talk about how it happens.
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. When that factor isn’t there, the cellular chain of events that happens in order for your blood to clot does not work effectively. Cue the diagram below1.
Because there are several clotting factors in your blood’s plasma, each factor is given a Roman numeral. Just like a certain end-of-the-season pro football game. For example, for factor eight, we use VIII1.
Our blood clots for a single reason: to prevent leakage of blood whenever there is a tear in the wall of a blood vessel. Less clotting factor means blood has difficulty clotting. And less clotting blood
isn’t what you want1.


To learn more about the clotting cascade, watch our video!
Types of Hemophilia
There are two main types of hemophilia: hemophilia A or classic hemophilia (which is a Factor VIII deficiency) and hemophilia B or, get this, Christmas Disease (a Factor IX deficiency). By the numbers, hemophilia A is about four times more common than hemophila B2.
On a scale from mild to severe
Severity in hemophilia is usually classified by the amount of clotting factor.
For example, severe hemophilia is where 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 muscles3. Moderate hemophilia patients have 1%-5% of the normal amount of clotting factor, which makes for some spontaneous bleeding and bleeding with trauma or surgery3.
Mild hemophilia, coming in with about 6-49% of the normal amount of clotting factor, commonly results in bleeding with major trauma or surgery3.
On a scale from mild to severe
Severity in hemophilia is usually classified by the amount of clotting factor.
For example, severe hemophilia is where 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 muscles3. Moderate hemophilia patients have 1%-5% of the normal amount of clotting factor, which makes for some spontaneous bleeding and bleeding with trauma or surgery3.
Mild hemophilia, coming in with about 6-49% of the normal amount of clotting factor, commonly results in bleeding with major trauma or surgery3.
On a scale from mild to severe
Severity in hemophilia is usually classified by the amount of clotting factor.
For example, severe hemophilia is where 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 muscles3. Moderate hemophilia patients have 1%-5% of the normal amount of clotting factor, which makes for some spontaneous bleeding and bleeding with trauma or surgery3.
Mild hemophilia, coming in with about 6-49% of the normal amount of clotting factor, commonly results in bleeding with major trauma or surgery3.
Genetics
More science.
This time: genetics
We know that the hemophilia gene is found on the X chromosome. Women have two X chromosomes and guys 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 pick up the slack. Guys don’t have that option, and that’s why hemophilia mostly occurs with men2.
Fact: up to one-third of new hemophilia cases have zero family history of the disease2. But you may have a great-great uncle who was a pirate.
To see how the gene is passed along between mothers and fathers
to their children, See diagrams4
Note for down the road: 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 HTC.4
Types of Bleeds
Joint bleeds
With severe hemophilia, about 85% of all bleeding happens in joints5. And they happen for no obvious reason. Blood fills the joint capsule, the joint swells then becomes painful and hard to move. The pressure from the swelling will eventually stop the bleeding, but you’ll feel it along with tingling, bubbling, warmth, pain or stiffness1.
Muscle bleeds
Muscle bleeds happen when the capillaries (tiny blood vessels) in a muscle are injured, from a fall or a bump or for no apparent reason. Muscle bleeds can cause muscles to feel stiff or painful. They can also bruise1.
Impact of bleeds
Over the long term, bleeds can lead to permanent damage. Joint bleeds can cause 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 walk1. So stay on top of this.
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 joint6.
1 World Federation of Hemophilia. Hemophilia in pictures. http://www.wfh.org/en/page.aspx?pid=1297. Accessed June 14, 2016.
2 World Federation of Hemophilia. Guidelines for the Management of Hemophilia. 2nd ed. 2012. http://www1.wfh.org/publications/files/pdf-1472.pdf. Accessed June 14, 2016.
3 National Hemophilia Foundation. Hemophilia A. https://www.hemophilia.org/Bleeding-Disorders/Types-of-Bleeding-Disorders/Hemophilia-A . Accessed June 14, 2016.
4 World Federation of Hemophilia. Symptomatic Carriers of Hemophilia. 2008.
5 Roosendaal G, Lafeber FP. Blood-induced joint damage in hemophilia. Semin Thromb Hemost. 2003;29(1):37-42.
6 National Hemophilia Foundation. Types of bleeds. http://www.hemophilia.org/Bleeding-Disorders/Types-of-Bleeds. Accessed June 14, 2016.
2 World Federation of Hemophilia. Guidelines for the Management of Hemophilia. 2nd ed. 2012. http://www1.wfh.org/publications/files/pdf-1472.pdf. Accessed June 14, 2016.
3 National Hemophilia Foundation. Hemophilia A. https://www.hemophilia.org/Bleeding-Disorders/Types-of-Bleeding-Disorders/Hemophilia-A . Accessed June 14, 2016.
4 World Federation of Hemophilia. Symptomatic Carriers of Hemophilia. 2008.
5 Roosendaal G, Lafeber FP. Blood-induced joint damage in hemophilia. Semin Thromb Hemost. 2003;29(1):37-42.
6 National Hemophilia Foundation. Types of bleeds. http://www.hemophilia.org/Bleeding-Disorders/Types-of-Bleeds. Accessed June 14, 2016.