Blood Drug Testing

Thyroid cancer blood test, VERY high T4, but low tsh.?

I am wondering what this means. My doctor didn't have time to explain the results of this. My recent blood work came back saying my T4 was really high, 35 or something like that. I am having slight simptoms of hyperthyroidism. I am on sythroid, 300mg dosage every day, very high dosage. I have been on this dosage for the past 6-7 months. I had a chest and neck x-ray done about a month prior to the blood work and it came out completely clear, no signs of cancer. I had the tumor removed and I have had radioactive iodine treatments done over the past two years. Since then my prognosis has been very good. So what is going on? Am I having a recurance or is my medication too high and maybe needs to be reduced? Or was the blood test a mistake? I had a re-test done last friday and im waiting on results today. I am very confused and need some answers. 19 male.

Public Comments

1. you need to calm down and wait to see what your doctor says. your doctor will do what is best for you.
2. I'm a bit confused by your history. Am i right in thinking you had a previous thyroid 'tumour' which was removed and therapy for high thyroxine levels. Now your thyroid is a bit low so you are taking supplements? If this is the case then with a high T4 (thyroid hormone) but a low TSH, this indicates that there is too much tyroid hormone present. This could either be due to tablets you're taking to increase the thyroid levels or it could be to an overactive thyroid.
3. TSH is Thyroid Stimulating Hormone. Its job in the body is to signal the thyroid gland to work harder. A high level means that your thyroid is underproducing and your body is trying to tell the thyroid to make more thyroid hormones such as thyroxine (T4). A low level means that there are plenty of thyroid hormones in the body and no more production is needed. It is an indirect measure, but pretty useful. T4 is one of the thyroid hormones (thyroxine). This is a direct measurement. So, it seems to me that a high T4 with a very low TSH would mean that your supplement is a little high and that your dose should be decreased. (High T4 means a high level of the supplement, and low TSH means the body doen't want any more.) My understanding of this is pretty basic though, so don't take my ideas too much to heart. Talk to your doctor, even if you have to slow him down a little.
4. Please go to the yahoo group for thyroid and aske them there. we had a lady on our group going thru the same thing, but she had thyroid cancer, T4 is not the cancer marker, it would be TG, and since you didn't have your entire thyroid out, I am pretty sure that is not reliable either. sometimes after changes in life, our dosages have to be changed.