Hello and welcome! It’s actually both. A diagnosis of one autoimmune disease does increase the likelihood of getting a second. For example, here is one study out of the UK that looked at about 2800 patients with autoimmune thyroid disease. About 10% of the Graves’ patients and 15% of the Hashimoto’s patients had a second autoimmune condition.
(Note on links: if you click directly on the following link, you will need to use your browser’s “back” button to return to the boards after viewing, or you will have to log back in to the forum. As an alternative, you can right-click the link and open it in a new tab or new window).
http://fpn.imng.com/fileadmin/content_pdf/fpn/archive_pdf/vol39iss3/70090_main.pdf
In terms of an initial diagnosis, the antibodies do have predictive value, but are not a *guarantee* that symptoms related to a specific condition will develop. For example, I sat in on a presentation this weekend where a doctor mentioned a study of patients with high levels of TPO antibodies, which is used to diagnose Hashimoto’s thyroiditis in a hypothyroid patient. However, only about half of the study group with high TPOab went on to develop overt hypothyroidism over a 20-year period.
So the real key is *awareness* of your risk of getting a specific autoimmune disease or of contracting a second autoimmune disease. Be aware of any new symptoms that develop and see your doctor as needed. With many autoimmune diseases, early detection can significantly improve the outcome.
Hope this helps!
