Graves' disease

Alternative names:

Basedow's disease; diffuse thyrotoxic goiter

Definition:

A disease associated with overactivity of the thyroid gland (hyperthyroidism).

Causes, incidence, and risk factors:

Located in the front of the neck just below the larynx, the thyroid gland is an important organ of the endocrine system. The thyroid gland secretes the hormones thyroxine (T4), triiodothyronine (T3), and calcitonin ,which control body metabolism and regulate calcium balance. The secretion of T3 and T4 by the thyroid is controlled by an endocrine feedback system involving the pituitary gland and the hypothalamus in the brain. Calcitonin is regulated by the amount of calcium in the blood and acts in conjunction with the parathyroid gland to control calcium levels. Since the thyroid gland is regulated by the pituitary gland and the hypothalamus, thyroid disorders may result not only from defects in the gland itself, but also from disruption of the control system. Thyroid disorders caused by overproduction of thyroid hormones are called hyperthyroidism, and underproduction of these hormones is known as hypothyroidism.

Graves' disease is one of most common causes of hyperthyroidism. The production of thyroid hormone is increased resulting in an enlarged thyroid gland and many changes within the body. The cause of the disease is unknown but may be related to a genetic or immune system disorder. Other disorders of the endocrine system may be present in people with Graves' disease. The symptoms of hyperthyroidism are present and, in addition, the eyeballs may protrude (exophthalmos) causing irritation and tearing. Risk factors are being female over 20 years old, although the disorder may occur at any age. The incidence is 5 out of 10,000 people.