Thank you for your question. I would strongly recommend that you speak with your primary care physician
or the doctor
who prescribed you the Thyronorm for further management, but here some general thoughts. TSH (thyroid stimulating hormone) is generated in the pituitary gland, and tells the thyroid to make more thyroid hormone (such as T4). Your initial labs with an elevated TSH and normal T4 are suggestive of "subclinical hypothyroidism," which means that your thyroid hormone levels were in a range that would be unlikely to cause you overt symptoms, but your brain was still trying to stimulate your thyroid to produce more thyroid hormone. When the TSH is greater than 10, most physicians recommend treating with a medication such as Thyronorm in order to prevent cardiovascular complications. However, there are other potential causes of an elevated TSH and normal T4 that may require different or only temporary treatment. For example, if you had a viral infection that affected the thyroid, the organ may have transiently produced less thyroid hormone, resulting in an elevation in TSH. As the thyroid recovers, T4 levels will normalize, but there will be a delay in the TSH returning to normal. There are also autoimmune causes of thyroid dysfunction that should be tested for in the right clinical context. Therefore, I strongly suggest meeting with your primary care physician to discuss some of the possibilities above and receive further guidance with regard to your medications. Best of luck!