If you have an over active thyroid you will not be able to keep weight on. An under active thyroid will make you gain weight. If your thyroid is not working right it can do those two things. If you are concerned then you need to see your Dr and have them run a test on your thyroid.
at 1:51 PM on Feb. 15, 2010
There aren't always symptoms related to weight, or otherwise. My ex has an underactive thyroid, which sometimes makes people gain weight, but he was 5'11" and weighed 155 lbs - so not overweight at all. He had no symptoms, other than an enlarged thyroid which he hadn't even noticed - the dr noticed it at a regular physical.