Coagulation disorders are a group of disorders that share the inability to form a proper blood clot. They are characterised by extended bleeding after injury, surgery, trauma or menstruation. Sometimes the bleeding is spontaneous, without a known or identifiable cause. Improper clotting can be caused by defects in blood components such as platelets and/or clotting proteins, also called clotting factors. The body produces 13 clotting factors. If any of them are defective or deficient, blood clotting is affected; a mild, moderate or severe bleeding disorder can result.