Severity And Bleeding 2016-11-07T21:10:05+00:00


The severity of hemophilia is determined by the level of clotting activity of factor VIII or factor IX in the blood. There are three levels of severity: mild, moderate, and severe. The following table shows the range of factor VIII and factor IX activity:

Normal range 50%-200% 0.5–2 IU
Subnormal range, but bleeding After injury is unlikely 25%-49% 0.25–0.49 IU
Mild hemophilia 6%-24% 0.06–0.24 IU
Moderate hemophilia 1%-5% 0.01 –0.05 IU
Severe hemophilia less than 1% less than 0.01 IU

*Percentage of normal factor activity in blood Number of international units (IU) per milliliter (ml) of whole blood.


Most bleeding in hemophilia occurs internally, into the joints or muscles. The joints that are usually affected are the ankle, knee, hip, elbow, and shoulder. Repeated bleeding without prompt treatment can damage the cartilage and the bone in the joint, leading to chronic arthritis and disability. Muscle bleeds most commonly occur in the upper arm, forearm, upper leg, calf, and iliopsoas muscle (the front of the groin area).

Some bleeds can be life-threatening and require immediate treatment. These include bleeds in the head, throat, gut, or iliopsoas. Bruises are very common in children with hemophilia. A bruise is not usually cause for alarm unless it is on the person’s head or neck, the person has a hard time moving, the bruise hurts, the lump in the bruise gets larger or does not go away, or if there is swelling, numbness, or a tingling feeling along with the bruising. If any of these symptoms are experienced, contact your physician or local hemophilia treatment center.

Mild hemophilia
  • Usually bleed only as a result of surgery or major injury.
  • May never have a bleeding problem.
Moderate hemophilia
  • Bleed less frequently,
  • Usually after an injury
  • Perhaps once a month.
  • Can bleed spontaneously.
Severe hemophilia
  • Usually bleed frequently into their muscles or joints.
  • May bleed one to two times per week.
  • Bleeding is often spontaneous (no obvious reason).