Hi and thanks for using the forum.
An ANA test looks for antinuclear antibodies in your blood. The presence of ANA in your blood indicates an autoimmune reaction. Most often, but not always, this type of reaction is caused by a connective tissue disorder (lupus, rheumatoid arthritis, etc.). An ANA is used in conjunction with other tests to narrow down the possibile autoimmune diseases. I hope this helps. Good luck..
Bridget
A positive ANA test is also very common in people with fibromyalgia even though fibromyalgia ia not an autoimmune disorder but a central nervous system disorder.