A condition in which there is not enough prothrombin in the blood, so that the person bleeds and bruises easily.
A deficiency of prothrombin (clotting factor) in the blood. As a result the affected individual tends to bleed more easily. The defect may be inherited or be the consequence of liver disease or of a deficiency in vitamin K. Anticoagulant therapy will also cause a fall in prothrombin levels.