An ANA test is a blood test that looks for antinuclear antibodies in your blood. Antibodies are proteins that your immune system makes to fight foreign substances, such as viruses and bacteria. But an antinuclear antibody attacks your own healthy cells instead. It's called "antinuclear" because it targets the nucleus (center) of the cells.
It's normal to have a few antinuclear antibodies in your blood. But a large number may be a sign of an autoimmune disorder . If you have an autoimmune disorder, your immune system attacks the cells of your organs and tissues by mistake. These disorders can cause serious health problems.
Other names: antinuclear antibody panel, fluorescent antinuclear antibody, FANA, ANA, ANA reflexive panel