Definition of Graves disease:

Graves disease is an autoimmune disorder that involves overactivity of the thyroid gland (hyperthyroidism).

Causes, incidence, and risk factors:

The thyroid gland is an important organ of the endocrine system. It is located in the front of the neck just below the voice box. This gland releases the hormones thyroxine (T4) and triiodothyronine (T3), which control body metabolism. Control of metabolism is critical in controlling mood, weight, and mental and physical energy levels.

If the body makes too much thyroid hormone, the condition is called hyperthyroidism. (An underactive thyroid leads to hypothyroidism.)

Graves disease is the most common cause of hyperthyroidism. The production of thyroid hormone is increased, causing a wide range of symptoms from anxiety and restlessness to insomnia and weight loss. In addition, the eyeballs may begin to stick out (exophthalmos), causing eye irritation and tearing.

Graves disease is caused by an abnormal immune system response that attacks the thyroid gland, and causes too much production of thyroid hormones. Risk factors are being a woman over 20 years old, although the disorder may occur at any age and may affect men as well.