The thyroid gland is a small, butterfly-shaped gland at the base of your neck. This small gland has a big effect on your body. The hormones it produces affect almost all bodily processes, including metabolism, fertility and sexual function, internal thermostat, mood, and more.

The American Thyroid Association estimates that more than 12% of Americans will develop a thyroid condition at some point in their life, although up to 60% of those with thyroid disease are unaware of their condition. Women are more likely than men to have thyroid problems, with around one in every eight women developing a problem at some point in her life.

Hyperthyroidism, in which too much thyroid hormone circulates in the body, is a common thyroid condition, affecting more than one in every hundred Americans. While there are many effective treatments for hyperthyroidism, uncontrolled hyperthyroidism can lead to serious, even life-threatening problems. Read on to learn more about what hyperthyroidism is, what the symptoms are, and how to live with this condition.