Thyroid TSH level of 36.9

by steve
(maidstone, kent,uk)

My 14 year old son has HYPOTHYROIDISM which has been managed by 100 Microgram’s of daily Thyroxine. He has just has his latest blood test results back which gave a TSH level of 39.6 (as told by the DR's receptionist.)Is this possible and is this a serious high level?

Under active thyroid gland versus non-compliance

Hi Steve, thanks for getting in touch about your sons thyroid function test results. The TSH level you quote is high indicating that the thyroid gland is under active, but it needs to be taken in the context of the T4 level or Thyroxine level as the TSH lags behind the T4 when correcting. You don’t mention when your son first started taking the Thyroxine as it takes a month or so to start making any difference to the levels.

If he has been on Thyroxine for sometime there could be 2 reasons for the high TSH level. It maybe that he needs a higher dose of Thyroxine which is entirely possible. Sometimes doses need to be higher than 100mcg. However, the other possibility is non-compliance with taking the medication. If he isn’t taking the medication the TSH will remain high. One way of checking this is comparing the latest TSH result with his presenting TSH result. If the TSH is improving then it is likely he is taking at least some if not all of the medication. You will need to liaise with his GP over this matter.

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