I have recently got very low levels of t3 and t4. my tsh is fine. i gained lot of weight and had a very high stress. do i need some treatment now ?

Just a thought: but your pituitary may be incapable of increasing the TSH and a "normal" level may actually be due to a lack of proper pituitary function (producing a higher TSH in the fact of low thyroid gland function. I would suggest a PITUITARY evaluation and after that is complete I would treat you with Thyroid replacement therapy! Hope this helps Dr Z