Your thyroid is a butterfly-shaped gland located at the base of your neck that makes and releases certain hormones. Its main job is to control your metabolism, which is how your body uses energy. Sometimes the thyroid doesn’t work as it should. This can lead to an overactive (hyper) or underactive (hypo) thyroid. Both conditions are treatable.

The thyroid gland makes two primary hormones – T3 (triiodothyronine) and T4 (thyroxine). They’re released into the bloodstream and carried to every tissue in the body, affecting almost every organ system. They help the body use energy, regulate your temperature. These hormones also help keep the brain, heart, gut, reproductive organs and other parts of your body working properly.

Sometimes, the thyroid doesn’t function as it should.

Hypothyroidism

When your thyroid doesn’t make enough hormones, the condition is called 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 brain 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 hypothyroidism than men. Women may experience changes in their menstrual cycles and issues with fertility.

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 medicine that replaces thyroid 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