You’ve been feeling fatigued and have gained some weight. It could be just a sign that you’re getting older, but there might be a chance these general symptoms are caused by hypothyroidism. Victor Bernet, M.D., an endocrinologist at Mayo Clinic, explains risk factors and how the condition is diagnosed and treated.

“Hypothyroidism is when the thyroid is making inadequate amounts of thyroid hormone,” Dr. Bernet explains. A blood test can confirm the condition, also called underactive thyroid.

Those at higher risk of hypothyroidism include women, people with a family history of thyroid disease, those with an autoimmune disease such as type 1 diabetes or celiac disease, people being treated for hyperthyroidism (when the thyroid gland makes too much thyroid hormone), those who have received radiation to the neck or upper chest or had thyroid surgery.

If you have an underactive thyroid gland, the symptoms may not be noticeable early on, but they can include fatigue, weight gain, dry skin, constipation, muscle pain, and swelling in the hands and feet.

“You just have one of these symptoms, the chances of hypothyroidism is going to be less than when you have a conglomeration of these symptoms all developing—that can be a big deal,” says Dr. Bernet.

Over time, if hypothyroidism isn’t treated, the symptoms can become worse and lead to other health issues, like high cholesterol and heart problems.

“The symptoms of hypothyroidism overlap with many other general medical issues. So it’s important, if you suspect yourself of having hypothyroidism, to go see your doctor and have some appropriate thyroid blood testing done,” says Dr. Bernet.

Often, treatment is simply taking daily oral thyroid medication to return hormone levels to a typical range. Treatment will likely be lifelong.