What Does Your Thyroid Do?

Everyone is born with a thyroid. It’s the “butterfly-shaped” gland in the lower front part of your neck. It sits right below the Adam’s Apple.

The thyroid gland makes two hormones — T3 (triiodothyronine) and T4 (thyroxine). Then the brain’s pituitary gland releases them into the bloodstream. Carried to every tissue in the body, these hormones help with many functions. They help the body use energy, stay warm and keep the brain, heart and other organs working properly.

Sometimes, the thyroid doesn’t function as it should. If it makes too little of the T3 and T4 hormones, it’s called hypothyroidism. When it makes too much of the hormones, it’s called hyperthyroidism.

Hypothyroidism

Hypothyroidism  is often caused by autoimmune disease, such as Hashimoto’s thyroiditis.  Other causes include radiation to the neck, some medications, surgical removal of the gland, a head injury, pregnancy and low levels of iodine in the diet. A family history of the disease can also mean that you are at higher risk for it.

Women have a higher risk for the disease than men. They may experience changes in their menstrual cycles. Common symptoms for men and women include unexplained weight gain, depression, fatigue, hair loss, dry skin, constipation, feeling cold, a slow heart rate, memory and concentration problems, and swelling in the neck.

Hypothyroid disease often progresses slowly. There may be no signs of the disease early on. When symptoms do show up, they may be subtle at first. Common early signs include fatigue and weight gain.

People often miss the signs because they think their symptoms are just part of getting older or caused by a different health issue. But if untreated, hypothyroidism can increase your risk for serious health problems like heart disease, infertility, depression and nerve damage.

Talk to your doctor if you have any of the symptoms, especially if they are new to you. Your doctor may ask you about your medical and family history to see if you have risk factors for thyroid disease. Hypothyroidism is diagnosed with a physical exam and blood tests.

The disease is treated with prescription medicine that restores T3 and T4 hormones to their correct levels so the body can function properly.

Hyperthyroidism

Hyperthyroidism  can be caused by several medical problems, including Graves’ Disease, thyroiditis, and lumps or nodules on the thyroid. Family history, some chronic diseases and pregnancy can raise your risk for hyperthyroidism.

There are many symptoms, including unexplained weight loss, hand tremors, dry skin, a rapid or irregular heartbeat, mood swings or anxiety, feeling weak or tired, muscle weakness, swelling in the neck, and trouble sleeping. Women may have changes in their menstrual cycle.

Like with hypothyroidism, symptoms may not be obvious at first and can be easily confused with other health issues. And it also causes serious health problems if not treated. It can lead to atrial fibrillation, congestive heart failure, vision problems and brittle bones.

Hyperthyroidism may be treated with medicines that stop the gland from making too much T3 and T4. Beta blockers may also be prescribed to slow hormone production. Sometimes treatment includes surgery to remove all or part of the thyroid gland.

If you think you may have any type of thyroid problem, talk with your doctor. Being proactive about your health can make a big difference in your quality of life.

Sources: Hypothyroidism,  American Thyroid Association; Hyperthyroidism,  American Thyroid Association; Hashimoto’s Disease,  Mayo Clinic, 2025; Thyroiditis,  WebMD, 2022; Hypothyroidism,  Mayo Clinic, 2022; Hyperthyroidism,  Mayo Clinic, 2022