What is hyperthyroidism?

Hyperthyroidism is a condition that occurs when a person’s thyroid is overactive. In other words, the thyroid gland produces too much thyroxine. Thyroxine is the main hormone that is secreted into the bloodstream by the thyroid gland. Hyperthyroidism is also known as thyroiditis, Grave’s disease, or thyrotoxicosis.


The thyroid gland sits in the front of the neck and is responsible for the release of hormones that control your metabolism, breathing, heart rate, nervous system, weight, body temperature, and many other bodily functions. When a person has hyperthyroidism, these bodily functions work faster and harder which causes a person to have anxiety, excessive perspiration, weight loss, rapid heartbeat, sleep problems, hand tremors, and other symptoms. About one percent of people in the United States have hyperthyroidism.

Hyperthyroidism is quite common. It occurs more often in women than in men. The signs and symptoms of hyperthyroidism include fatigue or muscle weakness, hand tremors, mood swings, nervousness or anxiety, rapid heartbeat, heart palpitations or irregular heartbeat, dry skin, difficulty sleeping, weight loss, increased frequency of bowel movements, and irregular periods such as light periods or skipping periods.

If left untreated, hyperthyroidism can cause a number of complications such as heart problems, brittle bones, eye problems, red and swollen skin, or thyrotoxic crisis. A person may develop heart problems such as a rapid heart rate, atrial fibrillation, or congestive heart failure. A person can develop brittle bones which is also known as osteoporosis. Too much thyroxine in the body can interfere with how the bones get calcium, which is essential for bone strength. Eye problems can develop such as red or swollen eyes, bulging, light sensitivity, blurring or double vision. This can lead to loss of vision. Skin problems include redness and swelling in the skin which usually appears on the feet and shins. Lastly, hyperthyroidism increases the risk for developing thyrotoxic crisis. Thyrotoxic crisis is when the symptoms of hyperthyroidism become suddenly intensified. This can cause a fever, a rapid pulse, and delirium. It is critical to get treated for this immediately.

To diagnose hyperthyroidism, your doctor will assess your medical history and do a physical examination as well as some blood tests so measure the levels of thyroxine and TSH in the blood. If these tests confirm hyperthyroidism, your doctor may also do a radioactive iodine uptake test or a thyroid scan to identify why your thyroid is overactive. Treatment for hyperthyroidism may include thyroid gland suppressants, radioactive iodine, beta-blockers for rapid heart rate and other symptoms, surgery to remove all or part of the thyroid gland, or thyroid replacement therapy if the thyroid gland is removed.