Overview and Facts about Hyperthyroidism
Hyperthyroidism occurs when the thyroid gland produces excess hormones in the body. The thyroid gland is located in the lower front of the neck and releases hormones that regulate several body functions, including the metabolism, heart rate, muscle strength and body temperature.
When the thyroid is overactive, it can lead to problems with the heart, bones, muscles, menstrual cycle and fertility.
Approximately 1% of people in the United States have hyperthyroidism, and women are 2 to 10 times more likely than men to be affected.
Signs and Symptoms of Hyperthyroidism
The thyroid is part of the endocrine system, which consists of a network of glands that produce and secrete hormones that the body uses for a range of functions. The thyroid makes two main hormones: triiodothyronine and thyroxine.
These hormones affect the cells and organs of the body and play several vital roles, including regulating the heartbeat, body temperature, and metabolism.
Symptoms of hyperthyroidism vary from person to person and may include:
- An enlarged thyroid gland
- Increased appetite
- Increased sweating
- Irritability and anxiety
- Menstruation changes
- Muscle weakness
- Rapid heartbeat
- Skin thinning
- Tremor in the hands
- Weight loss
Causes and Risk Factors of Hyperthyroidism
The most common cause of hyperthyroidism is Graves’ disease, a disorder caused by an abnormal immune system response, resulting in the thyroid making more hormone than the body needs.
Graves’ disease accounts for more than 70% of cases of hyperthyroidism. Other causes of hyperthyroidism include:
- Thyroid nodules, which are lumps in the thyroid gland (usually noncancerous) that may become overactive and trigger the production of excess hormones
- Thyroiditis, which is inflammation of the thyroid caused by an infection or a problem with the immune system, resulting in the gland leaking more thyroid hormones than are needed
Tests and Diagnosis of Hyperthyroidism
In addition to taking a medical history and performing a physical exam, an endocrinologist will order blood tests to measure the amount of thyroid hormones in the blood.
Imaging tests, such as a thyroid scan, are also typically performed to help determine the underlying cause, such as nodules or inflammation.
Treatment and Care of Hyperthyroidism
Treatment for hyperthyroidism depends on several factors, including the underlying cause and severity of the condition. Patients may need medication, radioiodine therapy or thyroid surgery.
Possible medications include:
- Antithyroid medicines that cause the thyroid to make less hormones. These drugs work well to control the overactive thyroid and don’t permanently damage the thyroid gland.
- Beta blockers to quickly relieve many of the symptoms of hyperthyroidism, such as rapid heartbeat and tremors.
Radioiodine therapy is another type of treatment that consists of taking radioactive iodine by mouth as a capsule. The iodine slowly destroys the cells of the thyroid gland that produce the thyroid hormone, causing the thyroid to shrink and thyroid hormone levels to decrease.
Surgery to remove the thyroid gland is reserved for patients with large nodules or for pregnant women who cannot take antithyroid medicines.
Removal of the thyroid gland will cause hypothyroidism (an underactive thyroid); patients who undergo this procedure must take thyroid supplements to keep hormone levels normal.