Thyroid Disease May Run in Your Family — and You Might Not Know It

Your thyroid gland plays a key role in making sure that your body operates at peak performance. It releases just the right amount of thyroid hormone to help regulate the body’s functions.

But if something is out of whack with your thyroid, you may experience:

• Hyperthyroidism: Your thyroid gland releases too much hormone, causing your body to kick into hyperdrive.
• Hypothyroidism: Too little hormone is released, making you feel like a sloth.

Thyroid diseases generally aren’t preventable. (If you’ve been avoiding soy or cauliflower to decrease your risk … that’s just a myth.) But according to endocrinologist Christian Nasr, MD, many thyroid diseases do run in families.

“Knowing your family history can help you stay one step ahead of complications from a thyroid disorder and related conditions,” he says.

Thyroid disease is often hereditary

“More than 75% of the time, patients with thyroid disease tell me that someone on one side of their family has thyroid disease,” says Dr. Nasr.

Autoimmune disorders seem to be a genetic link for some of the familial thyroid disorders, he notes. Autoimmune disorders occur when white blood cells go haywire and attack the cells that regulate body functions. The immune system’s foul play could cause the thyroid gland to produce too much or too little hormone. So having an autoimmune disease may increase your risk for thyroid disease, Dr. Nasr says.

But this same action — the white blood cells attacking body cells — could result in other autoimmune disorders like diabetes, lupus or rheumatoid arthritis, too.

“In a family, the same person could have an autoimmune disorder that causes hypothyroidism and another that causes diabetes,” says Dr. Nasr. “And you may have a different family member who has diabetes, but not thyroid disease.”

The takeaway: Inform your healthcare provider if any autoimmune diseases run in your family, even if there isn’t an obvious thyroid connection.

Genes play a role in thyroid cancers

Dr. Nasr has found that even thyroid cancers that aren’t considered hereditary can have a family link. “I’ve had situations where multiple family members have had the type of thyroid cancer that’s usually not hereditary,” he says.

Clustering of cancers in families isn’t unique to thyroid cancer. Some families carry a mutation that suppresses “good” genes in the body, which can put them at risk for a variety of cancers.

“Different syndromes can increase someone’s risk for certain types of cancer,” Dr. Nasr explains. “Cowden’s syndrome, for example, increases your risk of thyroid, breast and uterine cancers. Your family history may not include thyroid cancer, but if we see a lot of breast and uterine cancers, we may want to investigate whether there is a syndrome that puts you at risk for thyroid nodules or cancer.”

The takeaway: As with the autoimmune disorders, know your family history. This information helps your healthcare team find patterns that might indicate thyroid disease-causing gene mutations lurking in the background.

See your provider if you experience symptoms of thyroid disease

What if you don’t know about your family’s history with thyroid disease? These symptoms may indicate it’s time to seek medical care:

• A nodule or goiter: You have difficulty breathing or swallowing because of an enlarged thyroid or abnormal growth of cells that form a lump inside the thyroid.
• Hypothyroidism: You move at a snail’s pace. You can’t get your muscles to move. You’re always cold. You can no longer focus or comprehend things as quickly as you used to. Hypothyroidism symptoms tend to come on slowly, over time.
• Hyperthyroidism: You’re revved up all the time. You speak fast, move fast (and sweat a lot) and go to the bathroom frequently. People have a hard time keeping up with your conversation because you’re all over the map. As you might suspect, hyperthyroid symptoms tend to come on suddenly.

Once you’ve addressed your symptoms with your provider, they will likely perform a neck exam and a simple blood screening test. If all systems appear to be operating well, your doctor may recommend monitoring over time. If any of the results are concerning, your doctor may refer you to an endocrinologist or order an imaging test. And if you have a strong family history, genetic testing may help you make important healthcare decisions.