Monday Medical: Hyperthyroidism — Things to Know
March 11, 2019
Editor's note: This is Part 1 of a 2-part series about common issues with the thyroid gland. Part 2 will cover hypothyroidism, or the condition in which too little thyroid hormone is produced.
The thyroid is a butterfly-shaped gland in the neck that acts as the body's thermostat by producing just the right amount of thyroid hormone.
However, sometimes, it makes too much or too little. When that happens, a wide-range of symptoms can result.
Below, Dr. Jessica Devin, an endocrinologist with UCHealth Endocrinology Clinic in Steamboat Springs, outlines what to know about hyperthyroidism, a condition in which the thyroid makes too much hormone.
The thyroid gland makes two hormones that are secreted into the bloodstream: thyroxine, also known as T4, and triiodothyronine, also known as T3.
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"They affect so many things," Devin said. "Energy levels and metabolism; heart rate and temperature regulation; how quickly your bowels move; skin and hair; menstrual cycles. They can influence mood a lot, too."
Thyroid hormone is released in response to thyroid-stimulating hormone (TSH) from the pituitary gland. TSH levels then respond to how much thyroid hormone is released, similar to a check and balance system. If thyroid hormone levels are low, then TSH levels become high; if there's too much thyroid hormone, then TSH drops.
TSH level is often the first lab checked when a thyroid problem is suspected.
Why the excess?
Hyperthyroidism is often caused by Graves' disease, an autoimmune condition in which the thyroid gland is inappropriately stimulated to make too much hormone. Autoimmune diseases have a genetic component, so if you have a close relative with Celiac disease, Type 1 diabetes or a thyroid issue, you may be more susceptible.
The condition can also result from thyroid nodules or thyroiditis; the latter is an inflammation of the thyroid gland due to various causes such as viral illness or postpartum changes.
"When the thyroid gets inflamed, it can spill extra hormone into the blood," Devin said.
With hyperthyroidism, a blood test will reveal high levels of T4 and T3 and low levels of TSH. An ultrasound or scan can help determine what's causing the high levels and, therefore, how best to treat it.
Unexplained weight loss, feeling weak and washed out, tiredness, a racing heart, decreased endurance in exercise and a tremor are the main symptoms of hyperthyroidism. Graves' disease can also result in eye issues.
"People tend to have a hard time with mental clarity and focusing," Devin said. "It can feel like being on a lot of caffeine."
Because of unexpected weight loss or heart palpitations, hyperthyroidism is often more quickly diagnosed than hypothyroidism, which can result in weight gain or difficulty losing weight.
What to do
"Therapies are aimed at two things: treating the symptoms of hyperthyroidism or decreasing the synthesis of thyroid hormone," Devin said. "The therapy you use depends on the form of hyperthyroidism you have."
Often, medications are prescribed to slow down the thyroid gland. Radioactive iodine therapy may be used to gradually and permanently normalize the levels, while beta-blockers can help address heart palpitations. In rare cases, surgery may be necessary.
Left untreated, hyperthyroidism can result in bone loss, heart problems and other issues. "You definitely want to treat it," Devin said.
With any thyroid issue, iodine or thyroid supplements should be avoided.
"Those can be quite dangerous to take," Devin said. "They can influence thyroid hormone synthesis and can make the problem worse."
Similarly, people with hyperthyroidism should be aware of cold medications, which can further stimulate the heart rate.
With hyperthyroidism, patients can feel improvements quickly.
"While it can take months for levels to normalize, patients usually feel improvement within a few weeks with the right therapy," Devin said.
Susan Cunningham writes for UCHealth Yampa Valley Medical Center. She can be reached at email@example.com.