If your doctor thinks you might have lupus, they may ask you to take blood tests to check for antibodies in your blood. The most common antibody test is called the antinuclear antibody (ANA) test.

A very small number of people who test negative for antinuclear antibody (ANA) in the blood, which is a sign of the most common type of lupus, still have the condition. Lupus is an autoimmune disease ...