The symptoms of haemophilia depend on how severe the condition is, but the main sign is prolonged bleeding.
The bleeding may happen spontaneously. For example, this could be:
The bleeding may also happen after a medical or dental procedure, such as having a tooth removed.
The severity of haemophilia is determined by the level of clotting factors in a person's blood:
Children born with mild haemophilia may not have any symptoms for many years.
Mild haemophilia usually only becomes apparent after a wound or surgery, or a dental procedure such as having a tooth removed. These events could cause an unusually long period of bleeding.
Children with moderate haemophilia are affected in the same way as those with mild haemophilia, but they also bruise easily.
They may also have symptoms of internal bleeding around their joints, particularly if they have a knock or a fall that affects their joints. This is known as a joint bleed.
The symptoms usually begin with a tingling feeling of irritation and mild pain in the affected joint – most commonly the ankles, knees, and elbows. Less commonly, the shoulder, wrist, and hip joints can also be affected.
If a joint bleed is not treated, it can lead to:
The symptoms of severe haemophilia are similar to those of moderate haemophilia. However, joint bleeding is more frequent and severe.
Children with severe haemophilia have spontaneous bleeding. This means they start bleeding for no apparent reason.
For example, this could be:
Without treatment, people with severe haemophilia can develop:
There's a small risk of bleeding inside the skull, known as a brain or subarachnoid haemorrhage. It's estimated that 3 in 100 people with moderate or severe haemophilia will have a brain haemorrhage.
However, spontaneous bleeding inside the skull is uncommon and usually only caused by a head injury.
Bleeding in the skull should be treated as a medical emergency.
The symptoms of a brain haemorrhage include:
Call 999 for an ambulance if you think someone is having a brain haemorrhage.