Causes of Hyperthyroidism

• Graves’ disease — Graves’ disease is the most common cause of hyperthyroidism. In people with Graves’ disease, the immune system produces an antibody that stimulates the thyroid gland to produce too much thyroid hormone. Some people develop eye problems (called Graves’ ophthalmopathy), which causes dry, irritated or red eyes, and in severe cases may cause double vision. Others develop swelling behind or around the eyes that causes the eyes to bulge out.
• One or more thyroid nodules (small growths or lumps in the thyroid gland) can produce too much thyroid hormone. The nodule is then called a hot nodule, toxic nodule, or when there is more than one, a toxic nodular goiter.
• Painless (“silent or lymphocytic”) thyroiditis and postpartum thyroiditis are disorders in which the thyroid becomes temporarily inflamed and releases thyroid hormone into the bloodstream, causing hyperthyroidism.
• Subacute (granulomatous) thyroiditis is thought to be caused by a virus. It causes a painful, tender, enlarged thyroid gland. The thyroid becomes inflamed and releases thyroid hormone into the blood stream; the hyperthyroidism resolves when the viral infection improves, and may also be followed by several months of hypothyroid symptoms.
• Taking too much thyroid hormone medication for hypothyroidism.

Symptoms of Hyperthyroidism

• Anxiety, irritability, tremors, trouble sleeping
• Weakness
• Perspiring more than normal, difficulty tolerating hot weather
• Rapid, forceful, or irregular heartbeats
• Fatigue
• Weight loss in spite of a normal or increased appetite
• Frequent bowel movements

Diagnosis of Hyperthyroidism

Hyperthyroidism can be diagnosed with blood tests that measure the amount of thyroid hormone and thyroid-stimulating hormone (TSH).

Treatment

Hyperthyroidism can be treated using medicine, radioactive iodine, or surgery. Many factors, such as your age and the severity and type of hyperthyroidism, as well as your preferences, are important in determining which treatment is best. Endocrinologists frequently manage these treatments and refer to surgeons if an operation is required.