Haemophilia is an inherited (congenital) bleeding disorder that affects males. It is estimated that about 1 in 10,000 people have Haemophilia A or B.

Patients with haemophilia A have either no, decreased or defective production of the blood clotting protein, Factor VIII (FVIII). Those with haemophilia B have similar impairments with Factor IX (FIX). Haemophilia is said to be "severe" when the activity of the affected clotting factor (FVIII or FIX) is less than 1% of normal. Severe haemophilia is often associated with spontaneous bleeding (i.e. bleeding not caused by trauma or injury). Haemophilia is referred to as "moderate" when clotting factor activity is between 1% and 5% of normal, and "mild" when the relevant clotting factor activity is greater than 5%, but less than normal. Approximately 30-50% of haemophilia patients (depending on the type of haemophilia) have severe disease and can require treatment for bleeding several times per month.

Severe haemophilia usually becomes apparent in the first years of life – often when the child starts to move about independently. Haemorrhages often occur in the joints (particularly the weight bearing joints such as knees and ankles). These joint bleeds can cause severe pain and often permanent damage and disability if not treated properly. Other mild, moderate or even life-or-limb threatening bleeds can occur in the muscles, soft tissues, gastrointestinal tract or even the brain. In addition, trauma, major surgery, tooth extractions or other minor surgical interventions require medical treatment to manage the associated bleeding.

HQMMA/N7/0914/0067. November 2014.