What is haemophilia?
When a person’s blood cannot clot properly the condition is generally known as haemophilia. A person with haemophilia will not bleed any faster than anyone else following an injury, but they can bleed for longer. Worldwide more than 305,000 people have haemophilia. In 70% of all cases there is a family history of haemophilia. In as many as 30% of cases, either the mother may not be aware that she is a carrier, or the condition may have occurred spontaneously. The two most common types of haemophilia are haemophilia A and haemophilia B. The blood of people with haemophilia A has reduced levels of a protein called factor eight (written as VIII). The people with haemophilia B have reduced levels of a protein called factor nine (IX).Haemophilia is classified by how much of these proteins, known as clotting factors, there are in your blood. Mild haemophilia usually means a factor VIII or IX level of 10-50% of normal, moderate haemophilia usually means levels of 2-10% and severe less then 2%. Once established, the severity of haemophilia does not usually change during a person’s lifetime and people in the same family normally inherit the same level of severity of haemophilia.

Inheriting haemophilia – it’s in our genes 
Everyone’s body is made up of tiny cells, each of which contains 46 chromosomes, arranged in 23 pairs. These chromosomes, and in particular the so called ‘genes’ they contain, decide many of the things which make us into unique individuals, for example the colour of our hair and eyes. We inherit one half of each pair of chromosomes from our mother, the other comes from our father. Consequently we are a mixture of our mother’s and our father’s genes. That is why, whereas we may have blue eyes like our mother we may also have brown hair like our father. One of the pairs of chromosomes decides which sex we become. The individual sex chromosomes are called X and Y. Women have two X chromosomes, men have an X and a Y chromosome. Haemophilia is a ‘sex linked’ disorder. This means the gene for haemophilia is found on one of the sex chromosomes – the X chromosome. The diagrams on the right show what happens if a female carrier or a male with haemophilia has children. On both diagrams the X chromosome containing the haemophilia gene is shown in red. A woman carrying the haemophilia gene has a 50:50 chance of her son having haemophilia or her daughter being a carrier. All the daughters of a man with haemophilia will be carriers, but none of the sons will have haemophilia. If you are not aware of any previous history of haemophilia in your family your doctor may recommend that you and the rest of your family are tested. This will not only help identify any carriers in the family, but will also spot any other, as yet undiagnosed, haemophilia.

How blood clots and what happens in haemophilia
Typically when the body is injured blood clots to form a scab. This stops the bleeding and provides protection while the body repairs itself. In mild and moderate haemophilia this also happens, but sometimes the clot is weaker and breaks down before the repair process is finished which can mean that the bleeding restarts. This clotting process is very complicated and is often described in books using relay races or toppling dominos to help explain it.

The different ways blood clots in severe, moderate and mild haemophilia
To illustrate the difference between severe, moderate and mild haemophilia it might help to think of the amount of clotting factor in a person’s body like the amount of air in a football. Usually the ball is fully inflated, it can be kicked long distances and it can be bounced really high. In mild and moderate haemophilia the ball is not fully inflated, in fact it’s less than half full. The ball can still be kicked and bounced, but not as far or as high. It is not as easy to use as the fully inflated ball, but it still works. This is different to severe haemophilia where there is so little air in the ball that it is barely inflated at all. It cannot be used and it needs pumping up. This is why, in severe haemophilia, more treatment with factor is needed.

How will haemophilia affect me?
People with mild or moderate haemophilia do not usually have bleeding problems in everyday life. They tend only to have problems after an injury, an operation or dental treatment. Those with moderate haemophilia should nevertheless be aware that bleeds could happen from less severe injuries and that nosebleeds may be more frequent and last for longer. Make sure that you learn from the staff at your haemophilia centre how to recognise a bleed and what to do. In contrast to those with mild or moderate haemophilia, people with severe haemophilia have spontaneous bleeds into joints and muscles even when they have not been injured. They need treatment to stop these bleeds or to prevent them.

What is a Portacath?
A portacath is a special device that is put under the skin of the chest that is used to give an infusion of factor.

What is prophylaxis?
The word prophylaxis means a treatment that prevents something happening for people with haemophilia it means treatment to prevent bleeding. Some people with haemophilia have factor added to their blood on a regular basis whether they have had a bleed on not. This means that the factor will be in the blood ready to help out if a bleed occurs. The treatment is regular infusions of factor, usually three times a week. Think of it like bringing an umbrella out with you in case it starts to rain instead of waiting for it to rain and for you to get wet before getting your umbrella.