I seem to see this presentation quite often in my practice. How do I know if it’s due to Hashimoto’s or pituitary gland dysfunction? Based on TPO or thyroglobulin antibodies, I know with Hashimoto’s you don’t always have to see them. Do you have to do a TSH stimulation test?

Dr. Amy Nett:  Yes. I don’t know if you have to do the TSH stimulation test because is that actually going to affect your treatment initially? So if I see a low TSH and also low T3 and low T4, which honestly isn’t something I see a lot, I will order TPO thyroglobulin and also TSI antibodies. Because you’re saying low TSH, which is actually more often associated with hyperthyroidism or Graves’. So if you’re saying the low TSH, you’ll see a low TSH only in Hashimoto’s thyrotoxicosis or in Graves’ disease. So you can just monitor that and remember if it’s Hashimoto’s, you’re eventually going to go into more of a hypothyroidism with a higher TSH. So you do want to measure antibody levels, TPO, TG or thyroglobulin and TSI antibodies for a low TSH. Continue to monitor but I would not initially do a TSH stimulation test.