Haemophilia affects the body’s ability to control blood clotting, which is what is used to stop bleeding. It’s an inherited bleeding disorder, so if someone has haemophilia it’s likely one of their relatives will have it as well.

If someone comes to Great Ormond Street Hospital (GOSH) with haemophilia they’ll be treated by our Haemophilia specialty. 


Haemophilia is caused by a genetic defect. It’s an X-linked recessive condition (which means that boys have the condition, and girls carry it), caused by a lack of clotting factor proteins in the blood. 

Two thirds of all children born with haemophilia have a known family member who has or has had the condition too. The remaining third with the condition will have new genetic mutations which are responsible for causing it, and can be passed from the mother or from the child himself.  

Although the condition mainly affects boys, girls who carry the condition can also experience bleeding problems, for example if having dental extractions (having a tooth removed) or heavy menstrual periods. 


Symptoms can include internal or external ‘bleeds’ which can vary depending on how the condition affects people. 

Severe haemophilia commonly shows in babies and toddlers who have spontaneous or trauma-related joint, muscle or soft tissue bleeds, but can also show with trauma-related or mucosal bleeding (from the mucosal lining of areas such as your mouth or nose). 

Boys with moderate haemophilia might have spontaneous bleeds but are more likely to have trauma-related bleeding episodes.  

Mild forms of the condition only have prolonged bleeding after surgery or a trauma, like having a dental extraction. 


If someone has a known family history of haemophilia, or the mother is known to be a carrier, doctors may have taken a blood sample from the mother when she was nine weeks pregnant to check if her child was a boy or a girl. Women who are carriers of haemophilia have a 50 per cent chance of each male child being affected by the condition, so finding out the child's sex will have helped the doctors and the parents to plan a safe birth. 

More tests can be carried out when women have been pregnant for 12 weeks to see if their baby is affected by haemophilia, but it’s important to be aware that this does have risks of miscarriage. 

Baby boys whose mothers are carriers can be tested at birth from the umbilical cord to see if they have inherited haemophilia. Early diagnosis can also be made after other symptoms, like bleeding or bruising from a traumatic delivery, or prolonged bleeding from heel pricks (a blood test for newborn babies). 

Children without a family history of haemophilia will often not have bleeding problems until they are beginning to crawl or walk when they may develop joint or muscle bleeds or easy bruising. Less severe cases of haemophilia may not be diagnosed until later in childhood, usually as a result of injury, surgery or dental work.


Haemophilia can be treated by replacing the missing clotting factor in the blood, which is done using an injection into a vein. If someone has haemophilia A, they will need this treatment every 48 hours and if they have haemophilia B they will need it twice a week. This helps to decrease the number of bleeds had and minimise any joint damage that can happen after a bleed into a joint. 

Most children and young people at GOSH with haemophilia are treated using recombinant (genetically engineered) clotting factors VIII or IX. 

Boys might also have a venous access device (an implantable port which is inserted under the skin by a surgeon in hospital) which means treatment can be given at home. The clotting factor travels through a tube and into a lard blood vessel next to the heart. If someone has this treatment, their parents will be taught how to do it which gives more control over the condition. It can fit around everyday activities so life can be as normal as possible.  

Patients with haemophilia usually visit the hospital at least twice a year, but younger children come in more often. In this time we will review treatment progress and asses joint health too. 

Joint and muscle bleeds 

If a child has a joint or muscle bleed it will need to be treated with replacement for the missing clotting protein as soon as possible. When a bleed is happening the joint or muscle will feel hot, swollen and painful and it might be difficult to use that part of the body. We suggest using the acronym PRICE to help remember the steps in helping repair a muscle or joint bleed:

  • P – Protection. Take the weight off of the joint or muscle and keep it off for a couple of days. If it’s the ankle or knee, try using crutches.
  • R – Rest. Rest helps the healing process, so make sure to try not to use the joint or muscle for a few days. 
  • I – Ice. Ice can help with pain and swelling. Use an ice pack wrapped in a tea towel on the area for around 20 minutes maximum, and then repeat this every two hours. Or, put the ice pack directly on the skin.
  • C – Compression. Sometimes you can use an elasticated bandage to help reduce the swelling. Family members can help in applying one the right size.
  • E – Elevation. Keeping the blood away from the joint or muscle can help reduce swelling too. Try to keep the muscle or joint above the heart (so if it is the leg lie on the sofa with it on a pile of cushions, or if it is the arm put it in a sling). 

If it is a head injury, seek medical advice immediately.  


If someone has an acute bleed, they might see a physiotherapist who’ll make sure joints and muscles are working as they did before. He or she might ask the child to do certain stretches or strengthening exercises to help with this. A physiotherapist will also help minimise the risk of any damage to joints. 


Good dental care is important for people with haemophilia so make regular visits to the dentist. Dental reviews also happen at GOSH when children come for Haemophilia Centre appointments. 

Looking ahead 

Haemophilia is an inherited blood disorder so an adult male with haemophilia will have a normal son but any daughter will be a carrier. This means they have a 25 per cent chance of having an affected son and 25 per cent chance of having a carrier daughter in any pregnancy.  

People can talk to the medical team at GOSH if they have concerns about the future. They will be able to discuss these and answer any questions.

Last review date: 
July 2014