The process by which blood clots is complicated, involving a whole chain of different chemicals or factors in the blood, as well as tiny blood cells known as platelets. Problems with any of these factors, or platelets, may lead to delayed clotting.

When the blood is slow to clot, there's a risk that if you have surgery there'll be excessive bleeding the surgeon can't easily control. This could mean loss of a lot of blood, the need for transfusions, severe bruising, poor wound healing and even a fatal haemorrhage.

One of the most common bleeding disorders in women is called von Willebrand's disease (VWD). It affects about one in 100 women and is caused when a protein in blood necessary for proper clotting (known as von Willebrand factor or VWF) is deficient or doesn't work as it should.

This protein helps to carry factor VIII, another important blood clotting chemical, through the bloodstream, so if VWF is deficient, levels of factor VIII will be low, too.

There are several types of VWD, all of which are inherited. Levels of the factor may vary and may be sufficient to clot blood most of the time but not enough when you're having a major operation.

Platelet disorders are as common as VWD, but often go undiagnosed because the problem is usually mild and revealed only by situations such as the extra demands that surgery places on the clotting system.

These problems may be inherited, or caused by infections, medication (for example, aspirin interferes with platelet function, and so can many other drugs, including antidepressants and some heart drugs) or medical conditions including chronic kidney disease and some forms of leukaemia.

Rarer explanations for abnormal bleeding include haemophilia A (a deficiency of factor VIII itself rather than the protein that carries it around) and haemophilia B (a deficiency of factor IX). The severity of these genetic conditions varies from mild to very serious.

Haemophilia mostly affects men and is rare among women, but women carry the disease, passing it on to their sons.

Many of the women affected have clotting levels between about 30 per cent and 70 per cent of normal, and don't usually suffer from severe bleeding problems although heavy periods are a common symptom.

There are many other, much rarer bleeding disorders caused by deficiencies of less important proteins in the blood.

Each of these different problems needs a different treatment, which might consist of medicines to improve the platelets or supplements of the missing or low-clotting factors (using chemicals extracted from donated blood, or genetically engineered chemicals).

Your GP will be able to supply a clearer answer based on your particular circumstances.