An ANA screen measures the amount and pattern of antibodies in a patient’s blood that are working against his or her own body (autoimmune reaction).The antinuclear antibodies direct blood test is also known as an ANA Screen or an Antinuclear Antibodies Screen. Patients are not required to fast when preparing for this blood test. Walk-In Lab’s ANA screen is a confidential and convenient option for those without a doctor’s order, or without insurance. The antinuclear antibodies (ANA) direct blood test from Walk-In Lab is a cheap and convenient test that can be ordered online, and results are delivered within one to two days.When functioning properly, the body’s immune system attacks and destroys foreign substances such as bacteria and viruses. In autoimmune diseases, the immune system attacks and destroys the body’s normal tissues by producing antibodies that attach to the body’s own cells as though they were foreign substances. The antibodies will then damage or destroy the cells. Common autoimmune diseases include systemic lupus erythematosus (SLE or lupus) and Rheumatoid arthritis.Combined with a patient’s symptoms, physical examination and other tests, an ANA screen can help diagnose an autoimmune disease.