Warfarin is also used in the management of some other conditions.

Antiphospholipid Syndrome (also known as Antiphospholipid Antibody Syndrome or APS) is a condition which causes blood clots in both arteries and veins. This disease occurs due to a malfunction of the body's immune system (also called an 'autoimmune disease').

Warfarin is often used in this condition to reduce the risk of clot formation.

Protein C deficiency is a genetic trait that increases the risk of forming a blood clot.

Protien C is a natural anticoagulant that usually acts to regulate the clotting process.  It usually stops the formation of unneeded blood clots.

People with a deficiency of protein C have an increased risk of DVT.  Often if someone has a DVT and is found to have protein C deficiency they will need long-term anticoagulation therapy.

Factor V Leiden is a hereditary condition that increases the risk of forming a blood clot.

Normally, the clotter factor V is inactivated by protein C to stop excessive blood clots forming.  In this condition, clotting factor V is changed and can no longer be inactivated by protein C.  This means the clotting process continues and unneeded blood clots may form.

People with factor V Leiden are at an increased risk of DVT.  They may need anticoagulation therapy to reduce their risk of further clots.