What is hemophilia


What is hemophilia?

Hemophilia is a genetic (usually inherited) disorder that causes a person to have less clotting protein. Without enough clotting protein, the blood does not clot fast enough when tissue is injured. The 3 most common types of hemophilia are:

  • Factor VIII (8) also called Hemophilia A,
  • Factor IX (9) also called Hemophilia B, and
  • von Willebrand disease (vWD).

Sometimes, even with no family history of a bleeding disorder, someone can be a “spontaneous mutation” and have bleeding.

What does it mean to have a bleeding disorder?

Certain proteins in the blood, called factors, help platelets stick together to form clots that help the body heal itself. Hemophilia prevents the blood from forming a firm clot and results in a soft, unstable clot or no clot. People with hemophilia do not bleed faster than other people, they bleed continuously. The patient with von Willebrand Disease has non-functioning or decreased von Willebrand factor, so they, too, will bleed longer from nosebleeds, gum bleeds, or bleeds deep inside the body if they have a major internal injury.

Are there different types of vWD and hemophilia?

Yes, there are 4 main types of von Willebrand Disease:

  • Type 1: The level of von Willebrand factor in the blood is reduced. The symptoms can be so mild that the person is never diagnosed. People with Type 1 vWD usually do not bleed spontaneously but can have quite a bit of bleeding with trauma, surgery or when they have a tooth pulled.
  • Type 2: The von Willebrand factor has an abnormality. Within this type are two kinds of vWD:
    • Type 2A: The building blocks that make up the factor (called multimers) are smaller than usual or break down too easily.
    • Type 2B: The factor sticks to the platelets too well, leading to clumping of the platelets, which can cause a low platelet number.
    • Other type 2 subtypes exist but are rare.
  • Type 3: Patients have severe bleeding problems and have very low von Willebrand factor and factor VIII (the protein that helps with blood clotting).
  • Pseudo, or platelet-type vWD:  similar to Type 2B, but the defect is in the platelets instead of in the factor.

Hemophilia A and B also have 3 types each, based on the amount of factor VIII or factor IX in the body;

  • Mild means factor ranges from 5–40 percent of the normal amount,
  • Moderate means factor ranges from 1–5 percent, and
  • Severe means factor is less than 1 percent.

If you have a strong family history of the disease you should be tested. If a patient has severe hemophilia or Type 3 vWD, the family will usually find out at birth or by the time the child is a toddler.

How do I treat a bleed?

All people with bleeding disorders must have factor replacement supplies on hand at all times. In an emergency, like a head injury, the patient would need to take this factor replacement to the local emergency room. The factor would be mixed and infused into the arm through an IV. This puts the missing factor into the person so the blood will clot correctly.

Patients with severe hemophilia or Type 3vWD will need factor replacement infusions 1, 2, or 3 times a week depending on what the hematologist orders. A hematologist is a doctor who specializes in treating blood disorders. This doctor does blood tests to find out if someone has a bleeding disorder and writes the factor prescription if needed.

What do I need to know about having a bleed?

Infuse first! If it is a mild injury, do “RICE” steps. This stands for rest, ice, compression, and elevate. See “Do You Know… How to Treat a Bleed.” The sooner you infuse and follow up with RICE, the sooner the pain, swelling, and potential damage to the joint will be prevented. Even when you are in the emergency room, no X-ray, labs, or other tests should be done until a factor infusion is done first


To learn more about hemophilia and what to do if your child has a bleed, call the Blood Disorders Clinic at 901-595-5041. If you have an urgent need and cannot reach the Blood Disorders Clinic because it is afterhours or a holiday, call the main St. Jude number 901-595-3300 and ask to speak to the hematologist on call. If you are outside Memphis, dial toll-free 1-866-2STJUDE (1-866-278-5833).


This document is not intended to take the place of the care and attention of your personal physician or other professional medical services. Our aim is to promote active participation in your care and treatment by providing information and education. Questions about individual health concerns or specific treatment options should be discussed with your physician.

St. Jude complies with health care-related federal civil rights laws and does not discriminate on the basis of race, color, national origin, age, disability, or sex.

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