Graves Disease is the main cause of hyperthyroidism and is caused by a defect in the immune system. Autoimmune disease may be understood as a process by which the body sees some part of itself as being foreign and reacts to it much the same way that it would with any bacteria or virus. In the case of Graves' disease, the body sees the thyroid gland as the foreign object and produces antibodies that attack the thyroid gland.

This causes the thyroid gland to produce a greater than normal amount of the hormone called thyroxine. When you have excess thyroxine in your body, your metabolic rate can increase by 60 percent to 100 percent because thyroxine controls the metabolism of the cells. A higher metabolism can lead to a number of health problems, such as an irregular heartbeat or anxiety.

Signs and symptoms of Graves' disease and hyperthyroidism may include: Sensitivity to heat Weight loss, despite normal food intake Brittle hair Light menstrual periods Frequent bowel movements Restlessness  Muscle weakness Tremors Enlarged thyroid gland Increased sweating Nervousness & irritability Restless sleep Erratic behaviour Increased appetite Distracted attention span Fatigue Rapid heart beat Changes in sex drive

Graves Disease occurs mainly in middle aged women but can also occur in children and the elderly. Often, there is a genetic predisposition to autoimmune disorders but often the cause remains unknown. Of research importance, the Graves' gene in DNA has not yet been identified.

Graves' ophthalmopathy may cause these mild signs and symptoms: Excess tearing and sensation of grit or sand in either or both eyes Reddened or inflamed eyes Widening of the space between your eyelids Swelling of the lids and tissues around the eyes Light sensitivity

Less often, Graves' ophthalmopathy can produce these signs and symptoms: Ulcers on the cornea Double vision Limited eye movements Blurred or reduced vision

Graves Disease is incurable but not life threatening and is completely treatable. There are three standard ways of treating Graves' disease.

1. Anti-thyroid drugs which inhibit production or conversion of the active thyroid hormone; Most individuals do well on these medications and can continue them long term if they so choose. The most common side effect is a rash, which will require that the medication be stopped if it is severe.

2. Radioactive iodine which destroys part or all of the thyroid gland and renders it incapable of overproducing thyroid hormone. The treatment consists simply of swallowing a pill that contains radioactive iodine. Usually the treatment is entirely painless, though an occasional patient will notice mild soreness over the thyroid gland for a few days after the treatment.; or

3. Subtotal thyroidectomy, in which a surgeon removes most of the thyroid gland and renders it incapable of overproducing thyroid hormone. Surgery may be the best option in certain situations, such as patients with large multinodular goiters where the thyroid gland is interfering with swallowing

The more serious complications of prolonged, untreated, or improperly treated Graves' disease include weakened heart muscle leading to heart failure; osteoporosis, or possible severe emotional disorders.