What Causes Low TSH Level In A Thyroid Test?

Posted on Wed, 22 Jun 2016

Medically reviewed by Ask A Doctor - 24x7 Medical Review Team

Wed, 22 Jun 2016 Answered on

Wed, 20 Jul 2016 Last reviewed on

Question : IF my TH level is Low but my other Thyroid test were normal what is it that could cause the low TH level?

Answered by Dr. Mirjeta Guni (23 minutes later)

Brief Answer:
It is called subclinical hyperthyroidism!

Detailed Answer:
Welcome and thank you for asking on HCM!
I can understand your query.

In thyroid pathologies the TSH level is the first that changes, than in a more advanced stage change the FT4 and FT3.

This stage is called subclinical hyperthyroidism.
The most common causes are Graves' disease and nodular goiter.

In both cases there is an over production of the thyroid hormones (Ft4 and Ft3) that causes a suppression of the TSH level (hormone produced by the pituitary gland).

Hope your query is clarified, do not hesitate to ask if you have futher uncertainties.
Kind regards,

Dr.Mirjeta

Above answer was peer-reviewed by : Dr. Arnab Banerjee