Severity and symptoms

How severe is haemophilia?

People can have mild, moderate or severe haemophilia. The severity of haemophilia depends on the amount of clotting factor in the person's blood.

The normal level of factor VIII or IX in a person’s blood is between 50% and 150%.
Severity and factor level What to expect
Mild haemophilia

5% – 40% of normal clotting factor level

  • Usually only bleeding problems following a bad injury, having teeth taken out, surgery or medical procedures that pierce the skin.
  • Might never have a bleeding problem requiring medical attention.
  • Might not be diagnosed until later in life if not playing contact sports and have not had any injuries or operations.
  • Females might also have bleeding problems with periods (menstruation) or childbirth.
Moderate haemophilia

1% – 5% of normal clotting factor level
  • Might have bleeding problems with minor injuries, such as sporting injuries. 
  • Likely to have bleeding problems after having teeth taken out, surgery, medical procedures and/or a bad injury.
  • Occasionally have a bleeding episode for no obvious reason (‘spontaneous bleeds’).
Severe haemophilia

Less than 1% of normal clotting factor level
  • Often have bleeds into joints, muscles and soft tissues.
  • Can have bleeding episodes for no obvious reason (‘spontaneous bleeds’) as well as after surgery, dental work or injuries including minor bumps and knocks.
Please note: this table is a guide only.

Date last reviewed: August 2020
Important Note: This information was developed by Haemophilia Foundation Australia for education and information purposes only and does not replace advice from a treating health professional. Always see your health care provider for assessment and advice about your individual health before taking action or relying on published information.
This information may be printed or photocopied for educational purposes.