The thyroid produces two main hormones called T3 and T4. These hormones travel in your blood to all parts of your body controling the rate of many activities in your body, including how fast you burn calories and how fast your heart beats. These activities together are known as your body's metabolism. A thyroid that is working right will produce the right amounts of hormones needed to keep your body's metabolism working at a rate that is not too fast or too slow.
What is Hyperthyroidism?
Hyperthyroidism, also called overactive thyroid, is when too much thyroid hormone is made. Some disorders cause the thyroid to make more thyroid hormones than the body needs. The most common cause of hyperthyroidism is Graves' disease. Graves' disease is an autoimmune disorder, in which the body's own defense system, called the immune system, stimulates the thyroid, which causes it to make too much of the thyroid hormones. Hyperthyroidism can also be caused by thyroid nodules that prompt excess thyroid hormones to be made.
Symptoms of Hyperthyroidism
At first, you might not notice symptoms of hyperthyroidism. Symptoms usually begin slowly, but over time, a speeded up metabolism can cause symptoms such as:
- Weight loss, even if you eat the same or more food
- Eating more than usual
- Rapid or irregular heartbeat or pounding of your heart
- Anxiety
- Irritability
- Trouble sleeping
- Trembling in your hands and fingers
- Increased sweating
- Increased sensitivity to heat
- Muscle weakness
- More frequent bowel movements
- Less frequent menstrual periods with lighter than normal menstrual flow
Treatment of Hyperthyroidism
Treatment involves trying to reset your body's metabolism to a normal rate.
Source: U.S. Department of Health and Human Services