Hey MD, i havn't had any issues myself, but have scanned many a person who has.

Weightgain is definatly a side effect of hypothyroidism, as is tiredness, lethargy. On the other end of the scale, heart palpitations, weight loss, irritablitlity, inabilty to sleep, on edge all the time can be signs of a preson with hyperthyroidism.

A blood test is a great place to start to check your thyroid hormone levels. If indicated further testing can be done, such as a nuclear medicine thyroid scan and/or ultasound depending on the blood test results.

IF you had hypothyroidism, the cause would determine the treatment. If it was a global low hormone issue then this is generally recitified with oral Thyroxine tablets. If you had an over or under functioning nodule in the thyroid creating the issue, then this would be further investigated.

Thyroid issues can easily be dismissed as issues associated with having a new baby, like the tiredness etc. Might be worth a chat with the Dr and blood test.