What is hyperthyroidism?

Hyperthyroidism means your thyroid makes too much thyroid hormone. Your thyroid is a gland in the front of your neck . It controls your metabolism, which is how your body turns food into energy. It also affects your heart, muscles, bones, and cholesterol.
Having too much thyroid hormone can make a lot of things in your body speed up. You may lose weight quickly, have a fast heartbeat, sweat a lot, or feel nervous and moody. Or you may have no symptoms at all. While your doctor is doing a test for another reason, he or she may discover that you have hyperthyroidism.
Hyperthyroidism is easily treated. With treatment, you can lead a healthy life. Without treatment, hyperthyroidism can lead to serious heart problems, bone problems, and a dangerous condition called thyroid storm.