Why does a blood clot form?
Three factors may trigger a clot to form in a vein; A reduced blood flow allows the blood to clot in the vein which could be caused by immobility, surgery or long-distance travel over 3 hours Changes to the clotting mechanism which may be inherited, caused by some drugs or conditions such as pregnancy Damage to the lining of the vein allows the blood to clot which could be due to trauma, surgery or inflammation
