To detect antinuclear antibodies.
Antinuclear Antibodies (ANA). Guide. An antinuclear antibody (ANA) test measures the amount and pattern of antibodies in your blood that work against your own body (autoimmune reaction). The body's immune system normally attacks and destroys foreign substances such as bacteria and viruses.  Anti-Nuclear Antibody (ANA) Test. Anti-nuclear antibodies (ANA) are autoantibodies to the nuclei of your cells. 98% of all people with systemic lupus have a positive ANA test, making it the most sensitive diagnostic test for confirming diagnosis of the disease. Blood Tests Used in the Diagnosis of Lupus. Antibodies form in the body as a response to infection. When an invader (antigen) enters the body, white blood cells known as B lymphocytes react by making special types of proteins called antibodies. An ANA test may become positive before signs and symptoms of an autoimmune disease develop, so it may take time to tell the meaning of a positive ANA in a person who does not have symptoms. Conditions associated with a positive ANA test. The most common condition is SLE. 1  SLE—ANA are most commonly seen with SLE. 2  About 95% of those with SLE have a positive ANA test result. 3  If someone also has symptoms of SLE, such as arthritis, a rash, and skin sensitivity to light, then the person probably has SLE. First, some basic facts about diagnosing lupus: 1  Lab work alone cannot diagnose lupus. 2  97 percent of those with lupus will have a positive antinuclear antibody test (ANA). 3  It’s common for positive lab tests to come and go over time. 4  It’s very common to get somewhat different results at different labs.  Diseases and Conditions. There are more than 100 rheumatic diseases, including degenerative conditions such as osteoarthritis, inflammatory conditions such as rheumatoid arthritis and autoimmune diseases such as lupus.  Definition. An ANA test detects antinuclear antibodies (ANA) in your blood. Your immune system normally makes antibodies to help you fight infection. Why the Test is Ordered. According to the American Association for Clinical Chemistry, the ANA blood test is ordered when someone exhibits the signs and symptoms of an autoimmune disorder. Some symptoms of autoimmune disorders include low-grade fever, joint pain, body aches, skin rashes, and chronic fatigue.  Results. The presence of antinuclear antibodies is a positive test result. But having a positive result doesn't mean you have a disease. Many people with no disease have positive ANA tests — particularly women older than 65.  DESCRIPTION: When someone develops an autoimmune disorder their body produces antibodies to healthy organs and attacks them as if they were a disease. The antibodies that are produced to fight a person’s own cells can be measured in the blood using the ANA or antinuclear antibodies with Reflex Test. 
http://www.webmd.com/arthritis/antinuclear-antibodies-ana http://www.hopkinslupus.org/lupus-tests/lupus-blood-tests/ https://labtestsonline.org/understanding/analytes/ana/tab/test http://www.lupus.org/answers/entry/lupus-tests http://www.rheumatology.org/I-Am-A/Patient-Caregiver/Diseases-Conditions http://www.mayoclinic.org/tests-procedures/ana-test/basics/definition/PRC-20014566 http://www.brighthub.com/science/medical/articles/20317.aspx http://www.mayoclinic.org/tests-procedures/ana-test/basics/results/PRC-20014566 http://www.anylabtestnow.com/tests/ana-with-reflex-test/
what does ana blood test for