Is Something Off with Your Thyroid?

Your thyroid, the butterfly-shaped gland in your neck, has a mighty job: producing hormones that regulate nearly every system in the body, including metabolism, energy and brain function. But it's also prone to go on the fritz. More than 12 percent of Americans will develop a thyroid disorder in their lifetime, but up to 60 percent of them won't know it because the conditions are difficult to diagnose. The classic symptoms—sluggishness, weight loss, weight gain—can mimic those of chronic stress or other conditions and, as a result, can be overlooked by sufferers and their doctors. Don't let that happen to you.

The chance of receiving a thyroid cancer diagnosis has tripled in the last 30 years, making this the most rapidly increasing cancer in America—and women are three times more likely than men to develop the disease. While doctors estimate that part of this increase is due to overdiagnosis (one type of thyroid tumor has recently been downgraded from cancer), some invasive cases are also on the rise.

How to spot it: Women diagnosed with thyroid cancer are usually in their 40s or 50s. It doesn't always have noticeable warning signs, but you should see a doctor if you feel swelling or lumps in your neck or have trouble swallowing—and make sure your neck is examined at your annual physical.

To lower your risk: Lose weight. A recent study found that overweight people had a 25 percent higher risk of thyroid cancer; for those who are obese, the risk rose to 55 percent. The link is still unclear, but one possible explanation is that excess fat releases proteins that may contribute to tumor formation.

Common treatment: Removing the thyroid (some or all of it), followed by radioiodine therapy, a medication given in capsule or liquid form to destroy any remaining thyroid tissue and treat or prevent the spread of the cancer. For cases that don't respond to radioiodine therapy (5 to 15 percent of patients), a new drug called lenvatinib has been shown to shrink tumors in nearly 65 percent of progressive cases, according to one clinical trial.

This is the most common thyroid disorder, occurring when the gland doesn't produce enough hormones and, as a result, metabolism slows.

How to spot it: Symptoms range widely, from frequent constipation, low energy levels and shortness of breath to weight gain, depression and hair loss. Your doctor can check your levels of thyroid-stimulating hormone (TSH) using a simple blood test. (If TSH is high, thyroid levels are low.)

To lower your risk: Since some forms of hypothyroidism may be genetic, the best thing you can do is check your family's medical history in case you need to be on the lookout for red flags.

Common treatment: Levothyroxine, a synthetic version of the thyroid hormone T4, regulates metabolism and steadies hormonal imbalances.

This condition occurs when your thyroid is hyperactive and speeds up metabolism.

How to spot it: Telltale signs include sudden weight loss, a fast and irregular heartbeat, excessive sweating, difficulty sleeping and more frequent bowel movements.

To lower your risk: Don't smoke; lighting up is associated with a greater risk of Graves' disease, the most common cause of hyperthyroidism in the U.S.

Common treatment: Radioiodine, which is given orally to shrink the thyroid and help get it back on track, is the first course of action. Make sure your doctor keeps tabs on your blood work—the substance will often cause you to underproduce T4, leaving you with hypothyroidism, which has fewer long-term complications.

Try this! Fill up on vitamin D. Deficiency of this vitamin has been linked to both hyper- and hypothyroidism. Fatty fish are the best food sources of D: One serving of salmon provides more than the recommended dietary intake for a whole day.