Underactive thyroid disease, medication and risk to women

Q: My sister was diagnosed recently with Hashimoto’s thyroiditis. She mentioned having to take medication and being on a special diet. Is there anything else she can do to manage symptoms? Am I am at risk for this condition too?

A: Hashimoto’s thyroiditis is a condition in which your immune system attacks your thyroid. It is named after a Japanese physician who first described the condition in the early 1900s. Hashimoto’s thyroiditis, also known as Hashimoto’s disease, is the most common cause of hypothyroidism, or underactive thyroid, in the U.S.

Women experience thyroid problems in far greater numbers than men, and it is estimated that 1 in 8 women can develop a thyroid condition during their lifetime. While Hashimoto’s thyroiditis primarily affects middleaged women, it also occurs in women of any age, as well as in men and children.

People who get Hashimoto’s thyroiditis often have family members who have thyroid disease or other autoimmune diseases. While you may not have any symptoms of thyroid issues now, you can speak to your health care provider about whether you should have your thyroid checked.

Hashimoto’s thyroiditis typically progresses slowly, over years. In some cases, people may not notice the signs or symptoms, as thyroid function can be normal. However, in most cases, a decrease in thyroid hormone production results in chronic inflammation. People may first notice a swelling at the front of the throat.

Other signs and symptoms of hypothyroidism may include fatigue, feeling cold, unexplained weight gain, dry skin, depressed mood, memory issues, constipation, menstrual changes, muscle weakness, or aches and pain. Fertility may be a sign for some women. Some patients with hypothyroidism may go undiagnosed for prolonged periods of time.

Recommendations for managing thyroid levels are based on clinical factors, so each person may be different. In some cases, close monitoring with serial thyroid blood tests will be advisable, while in other cases, initiation of thyroid hormone replacement therapy may be indicated. Your sister should visit with an endocrinologist who can help her effectively manage her condition.

Most patients with hypothyroidism requiring therapy can be successfully managed with an oral medication called levothyroxine. Choices include generic or brand-name forms of this medication that need be taken once daily. Your health care team can advise you in more detail about these options.

If hypothyroidism is the cause of a person’s symptoms, the symptoms should gradually resolve once thyroid hormone levels are back in the normal range. After thyroid hormone replacement therapy is started, thyroid blood tests are typically checked about every six weeks until the levels are in target range and felt to be stable. Subsequent tests may be performed every six months to one year.

Your sister should schedule follow-up visits as often as her health care provider recommends. It’s important to make sure she is receiving the correct dose of medicine. Over time, the dose she needs to adequately replace her thyroid function may change.

The only other caveat is that if your sister’s symptoms persist despite medication and thyroid levels evening out, it is possible that the symptoms may be related to another underlying condition other than the thyroid. Further evaluation for other potential causes of the symptoms is then warranted.

— Victor Bernet, M.D., Endocrinology, Diabetes and Metabolism, Mayo Clinic, Jacksonville, Florida

Mayo Clinic Q&A is an educational resource and doesn’t replace regular medical care. Email questions to MayoClinicQ&A@ mayo.edu.