Lupus anticoagulants are antibodies against substances in the lining of the cells. These substances prevent blood clotting which are called phospholipids. People with antibodies to phospholipids may have a high risk of forming blood clots.
It is usually ordered with other related tests when someone has an unexplained blood clot in a vein or artery, with symptoms ranging to deep vein thrombosis and pulmonary embolism, if a woman experiences recurrent miscarriages, a person with the signs and symptoms of APS, etc. If the tests return positive, it is normally followed up with another test after 12 weeks to confirm that the condition is still present.