In teens who have hyperthyroidism, the thyroid gland makes and releases too much thyroid hormone. The body’s functions speed up, and this causes a range of symptoms. An overactive thyroid, or ...

Your thyroid is a small butterfly-shaped gland in your neck that controls how quickly every cell in your body uses energy.

Hyperthyroidism causes high levels of thyroid hormones in the body. In some cases, people with high thyroid hormone levels may also have higher calcium levels. Thyroid hormones can affect many ...