Hyperthyroidism is a disorder that is caused by elevated levels of thyroid hormone.

What is going on in the body?

The thyroid gland is a small endocrine gland located at the base of the neck. It produces thyroid hormone, which controls the processes which allow the body to transform food into energy and to rebuild cells. In a person with hyperthyroidism, the body produces too much thyroid hormone.

What are the causes and risks of the condition?

There are several causes of hyperthyroidism. In some people, the immune system produces antibodies that activate and stimulate the thyroid gland. This causes the gland to produce excessive amounts of hormones. A common example of this is Graves' disease. Other forms of hyperthyroidism may be caused by thyroiditis, or inflammation of the thyroid gland. Certain benign or malignant tumors can also produce too much thyroid hormone. Some forms of goiters can enlarge and produce excess thyroid hormone.