What does severity mean?
There are three types of haemophilia: mild, moderate and severe. The level of severity depends on how much clotting factor VIII (8) or IX (9) is in the person’s blood naturally. A person with haemophilia will have the same level of severity their whole life, e.g. someone with severe haemophilia will always have severe haemophilia. Within a family, males will also inherit the same level of severity, e.g. if a grandfather has severe haemophilia and his grandson has inherited haemophilia, his grandson will also have severe haemophilia. However, this is not the same for females. For example, a girl whose father has severe haemophilia may have the same factor levels and symptoms as a girl whose father has mild haemophilia.
For a person who doesn’t have haemophilia, the range of factor VIII (8) and factor IX (9) in their blood is usually between 50% and 200%
5 – 40% of normal clotting factor
- Usually only have bleeding problems after having teeth taken out, surgery or a bad injury or accident
- Might never experience a bleeding problem.
1 – 5% of normal clotting factor
- Might have bleeding problems after having teeth taken out, surgery or a bad injury or accident
- Might have a bleed about once a month
- Rarely have a bleed for no obvious reason.
Less than 1% of normal clotting factor
Date last reviewed: 21/06/2012
- Often have bleeds into joints, muscles and soft tissues
- Can have bleeds for no obvious reason, as well as after surgery, dental work or injuries including minor bumps or knocks
- Might have a bleed once or twice a week