If you haven’t been diagnosed with a thyroid disorder, you know someone who has. Thyroid disorders are common, and about 12% of Americans will experience abnormal thyroid function at some point during their lives. If you’re really into numbers, here are some that might surprise you:

• An estimated 20 million Americans have some form of thyroid disease.
• Up to 60 percent of those with thyroid disease are unaware of their condition.
• About 4.6% of the U.S. population (12 years old and older) has hypothyroidism.
• Women are five to eight times more likely than men to have thyroid...