How low is too low for a TSH level?

[Yabba-Dabba-Doo]

I just had my TSH tested and it is showing a result of 0.01. Normals with this test are mU/L 0.6 - 6.0. I am currently taking .125 mg. of Synthroid.

I've been feeling just dreadful with zero energy and a lot of tiredness plus leg weakness. My skin is extremely dry.

I'm 39 and female and have a 4 mm. pituitary tumor.

With a level of .01 am I still hypothryoid or am I now hyperthyroid?

Thank-you for your help!

Yabba

[Caddy B]

My TSH is less than 0.35 when I am on an optimal amount and
mostly symptom free. And I am *not* hyper. Once you are on treatment, the feedback loop of the TSH means very little.

Many patients on thyroid replacement therapy achieve a sense of wellbeing only when TSH is low or undetectable.

A patient with a suppressed TSH on thyroid replacement therapy
does not have the same risk as a person who is not on thyroid replacement therapy, with a suppressed TSH. Having Hashimoto's, I speak from experience!  Thankfully I have a doctor who treats my symptoms and *not* my Lab test results.

[ancientmariner]

Look up secondary hypothyroidism, also known as pituitary hypothyroidism. You have a pituitary tumor? Well, the TSH measures a PITUITARY hormone, not a thyroid hormone. So, if you have a pituitary tumor, it certainly makes sense that your pituitary may not be trying to stimulate the thyroid, hence the low TSH. Ask your doctors to test actual thyroid hormones, T3 and T4, preferably the Free T3 and T4. Free T3 is the amount of unbound thyroid hormone in your blood that is immediately available for use. It is the active hormone. Free T4 is the amount of unbound storage hormone available to be converted to T3 as needed. These measures would be a much better indication of your thyroid status than the TSH!!!

[rasshy]

A related discussion, am i hyper or hypo thyroid? was started.

[djayne]

A related discussion, tsh result is 0.04 was started.

[Mark Lupo, M.D.]

Typically a TSH of 0.01 in such a case means you are hyperthyroid due to over-treatment with thyroid hormone of the hyppothyroidism.  A TSH <0.2 concerns me for over-stimulation of the heart and for bone loss.  You may want to decrease the dose of synthroid and also consider asking your doc about combination t4/t3 therapy (ie, adding a small dose of cytomel to the synthroid).  The 4mm pituitary adenoma is not likely contributing but does need follow-up.