Hyperthyroidism: Things to know

March 22, 2019
A couple stands in a field in this photo.
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. Photo by Getty Images.


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.

Thyroid 101

The thyroid gland makes two hormones that are secreted into the bloodstream: thyroxine, also known as T4, and triiodothyronine, also known as T3.

“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? Common cause of hyperthyroidism

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.

Common symptoms

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.

Treated hyperthyroidism: 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.

Cautions: antithyroid drugs and side effects

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.


This article first appeared in the Steamboat Pilot & Today on March 11, 2019.

About the author

Susan Cunningham lives in the Colorado Rocky Mountains with her husband and two daughters. She enjoys science nearly as much as writing: she’s traveled to the bottom of the ocean via submarine to observe life at hydrothermal vents, camped out on an island of birds to study tern behavior, and now spends time in an office writing and analyzing data. She blogs about writing and science at susancunninghambooks.com.