What is an ANA test?

The ANA (anti-nuclear antibody) test is a type of blood test that checks for autoimmune disorders, such as Sjögren's Disease or lupus. In this test, a sample of your blood is taken and tested with a special fluorescent dye that glows under a microscope. If certain anti-nuclear antibodies are present in your blood, it illuminates, indicating a positive result.

A positive result does not necessarily mean you have an illness, as healthy people can also test positive. The result is often given as a ratio, which represents how much your blood sample was diluted before the glow was no longer seen. Common ratios include 1:40, 1:80, 1:160, 1:320, and 1:640. It's worth noting that even among healthy people, up to 15% may show a ratio of 1:80 and 5% a ratio of 1:160.

Also, having a negative ANA test does not completely rule out the possibility of having Sjögren's Disease. Some individuals with a negative ANA test might still have specific antibodies associated with the condition.

Interestingly, the illumination can also form different patterns under the microscope. For people with Sjögren's Disease, the most common patterns are a speckled or a homogenous pattern. But remember, these patterns are just part of the overall analysis and do not provide a diagnosis on their own.