18/11/2023
When someone has Hashimoto’s, we typically expect that they will end up with an underactive thyroid. In this case, they are usually prescribed medications like Thyroxine to bring their thyroid results back into range.
Occasionally however, an individual with Hashimoto’s will swing into hyperthyroidism (an overactive thyroid). There can be a few reasons for this - like postpartum thyroiditis or taking too much thyroid hormone - but one lesser known cause is Hash*toxicosis. Hash*toxicosis is an overactive thyroid that occurs as a result of Hashimoto’s, and not due to external factors like medications or pregnancy.
In Hash*toxicosis, the initial autoimmune attack on the thyroid causes destruction of the thyroid follicles, resulting in a passive letdown of thyroid hormones into the bloodstream. The thyroid isn’t MAKING too much thyroid hormone. It is passively RELEASING thyroid hormone as its cells become damaged and release their contents. As a result, we see an increase in thyroid hormone levels, sometimes to the extent of full blown hyperthyroidism. Although this hyperthyroidism is temporary, it can be severe enough in some cases to warrant treatment.
When I first diagnosed with Hashimoto’s, my thyroid antibodies were in the thousands, and instead of being hypothyroid, my TSH was 0.009. I was subclinical hyperthyroid. One month later, my TSH was 5.96. I had swung into hypothyroidism.
My experience followed the typical trajectory expected of Hash*toxicosis: it is often the first step in the progression into Hashimoto’s hypothyroidism, but unless we do bloods at this point, we don’t always catch it happening. After an initial period of hyperthyroidism, most individuals will become temporarily euthyroid (meaning their thyroid levels appear ‘normal’), before finally progressing into hypothyroidism. At this point, the thyroid is no longer able to sustain normal thyroid hormone production due to the autoimmune process.
Just recently I was going through my old blood tests and thought I might share my journey with Hashimoto’s and Graves’ through my results. Is this something you would be interested in? What has your journey with thyroid issues looked like?