The Cardiolipin Antibodies test measures the levels of IgG and IgM antibodies directed against cardiolipin, a phospholipid present in cell membranes. The presence of these antibodies may indicate an increased risk of blood clot formation and is commonly associated with autoimmune conditions, particularly Antiphospholipid Syndrome (APS). This test is often performed in patients with a history of unexplained blood clots, recurrent pregnancy loss, or suspected autoimmune disorders.