The thyroid gland also known as the “master gland” of the body has many functions. It controls body temperature, how well you sleep, your cholesterol levels, energy level and blood pressure, to just name a few.
Another major function the thyroid gland has is weight management. The two hormones that the thyroid produces that will affect weight gain or loss are T3 (triiodothyronine)
In both cases there can be difficulties with weight control.
Savard, a thyroid cancer survivor, knows all to well the trials of being in a hypo and a hyper state. Her e-book "The Thyroid Gland In Simple Terms", found at http://www.papillarythyroidcancerguide.com does just as the title states, explains the different aspects of the gland located at the base of your neck.