Anti-cardiolipin antibodies are mainly checked for systemic lupus erythematosus and its autoimmune diseases. many causes are closely related to the production of anti-cardiolipin antibodies, and the common causes are as follows: 1. autoimmune diseases: such as systemic lupus erythematosus, rheumatoid arthritis and scleroderma. 2. viral infections: such as adenovirus, rubella virus, varicella virus, mumps and other viral infections. 3. other diseases: such as Mycoplasma systemic disease. 4. Drug conditions: Oral administration of certain drugs, such as chlorpromazine and phenothiazine, can also lead to abnormalities in anticardiolipin antibodies, especially in a small number of normal individuals without obvious organic disease, especially in the elderly. The immunological typing of anti-cardiolipin antibodies includes IgG, IgA and IgM, of which IgG is the most clinically significant and is usually determined by enzyme-linked immunosorbent assay.