Hyperthyroidism is a result of overactivity of the thyroid gland, which sits just below the Adam’s apple in the neck. This gland secretes hormones that regulate a person’s metabolism, the physical and chemical processes necessary to maintain life.

Patients with hyperthyroidism experience the release of too much thyroid hormone. As a result, processes in the body speed up, and the patient may experience symptoms such as thyroid enlargement (goiter) and sudden unexplained weight loss. In some cases, hyperthyroidism also affects the eyes and the skin, particularly on the shins and feet.

Several disorders can cause hyperthyroidism. They include:

• Graves’ disease. An autoimmune disorder in which antibodies stimulate the thyroid to produce too much thyroid hormone.
  
  
• Hyperfunctioning thyroid nodules. Occurs when lumps in the thyroid, which are generally noncancerous, produce too much thyroid hormone.
  
  
• Thyroiditis. Inflammation of the thyroid gland, which allows excess hormones to leak into the bloodstream.

Diagnosing hyperthyroidism can be difficult because symptoms may mimic those of other conditions. A physical examination often reveals signs and symptoms such as eye problems or brittle hair. Thyroid blood tests aid in diagnosis.

There are various treatments available to treat patients with hyperthyroidism. Radioactive iodine can be taken in pill or liquid form to shrink the thyroid gland, reducing symptoms. Antithyroid medications and surgery also may be used. Some therapies affect the thyroid gland so significantly that patients may be required to take supplements to ensure that they receive proper levels of thyroid hormone.