What is Hyperthyroidism?
What is the Thyroid?
The thyroid is a gland that is a component of our endocrine or hormonal system that is primarily responsible for our body’s metabolism as well as playing a smaller role in our body’s calcium balance.
The thyroid is located in the neck and is butterfly-shaped, about two inches in size and consisting of two lobes (i.e. the butterfly wings). The thyroid’s most important function is to produce two iodine-containing thyroid hormones, triiodothyronine (T3) and thyroxine (T4). The thyroid is controlled by the pituitary, another gland located within the brain, that produces thyroid stimulating hormone (TSH) leading to stimulation of the thyroid to produce T3 and T4. T3 and T4 are primarily involved in controlling our body’s metabolism or energy level, growth and development, and body temperature. The thyroid is also responsible for secreting another hormone called calcitonin which plays a role in calcium homeostasis.
What is Hyperthyroidism?
Hyperthyroidism is medical term for when a person makes too much thyroid hormone. Most people complain of symptoms such as anxiety, fatigue and feeling shaky. The most common cause of hyperthyroidism is called Graves’ disease and occurs when ones own body causes the thyroid to release too much thyroid hormone in turn causing the gland to become enlarged (called a goiter). This condition is more commonly seen in younger women between the ages of 20 and 40. Some people will go on to develop dry, red eyes or even leading to swelling around the eyes that cause the eyes to protrude out and lead to excessive lid opening.
Other things that can lead to excessive thyroid hormone release include thyroid nodules (small growth or lumps in the thyroid gland), thyroiditis in which the thyroid gland is temporary inflamed leading to a release of excess thyroid hormones, and lastly, can happen when one takes too much thyroid medication if they were being treated for low levels of thyroid hormones.
What are the symptoms?
The symptoms of hyperthyroidism differ from person to person. Some people who have hyperthyroidism have no symptoms. The best way to think about these symptoms is to imagine your body in overdrive: people complain of symptoms such as anxiety, irritability, trouble sleeping, weakness, trembling, excessive sweating, heat intolerance, fast or uneven heartbeats, weight loss with no change in diet, and frequent bowel movements. In terms of other physical changes, one may notice a lump or swelling of the neck at the location of the thyroid gland called a goiter. If Graves’ disease causes hyperthyroidism as described above, it may cause a persons eyes to bulge.
It is important to note that if this condition goes untreated, it can cause an irregular heart rhythm known as “atrial fibrillation” leading to chest pain and possible heart failure. In women, hyperthyroidism can lead to difficulty getting pregnant due to disruptions in monthly menstrual cycles while some men could experience breast growth and sexual dysfunction.
How to test for it
When your doctor thinks there may be a problem with your thyroid gland, he or she will order a simple blood test that shows the level of TSH (the hormone that stimulates the thyroid to make T3 and T4). The level of TSH will be high or low and will correlate with the opposite syndrome, i.e high TSH means you have decreased thyroid hormones while low TSH means you are making an excess of thyroid hormones. A thyroid scan or ultrasound may also be recommended to help determine the cause of hyperthyroidism which could detect nodules or other causes of disease.
Hyperthyroidism has multiple aspects of treatment including medication, radioactive iodine, or surgery. Your age, degree of disease and source of hyperthyroidism are important in determining which treatment is best.
The medications include a) anti-thyroid drugs, such as methimazole and propylthiouracil (PTU), that lead the thyroid to decrease how much hormone it makes and b) beta-blocker medicines that help reduce the symptoms of hyperthyroidism and allow one to feel more comfortable until the thyroid imbalance is under control.
Up to 50 to 70 percent of people with mild Grave’s disease will go into remission. However relapse of disease is still possible at which time most doctors would advise need for permanent treatment with radioactive iodine or surgery.
Destroying the thyroid with radioactive iodine, called ablation, is a permanent way to treat hyperthyroidism. Radioactive iodine, which comes in a pill or liquid you swallow, works by destroying much of the thyroid gland. Pregnant women should not use this treatment, because it can damage the baby’s thyroid gland. But the treatment is safe for women who are not pregnant and for men. Ablation with radioactive iodine is currently a commonly used treatment for hyperthyroidism in the United States.
Lastly, surgery can be performed to remove part of the thyroid (for example, if the symptoms were being caused by a single nodule producing excess hormone) or the entire gland. This treatment is a much simpler and straightforward means to manage hyperthyroidism. Surgery is an outpatient procedure that takes 45 minutes and prevents the unnecessary complications and side effects of radioactive iodine.