Thyroid: When to worry

I get this question often: “I’ve been gaining weight, feeling sluggish. Do I have a thyroid problem? My aunt has it.”

Or if you’re in the habit of consulting Dr. Google, I bet the word “thyroid” pops up lots. What’s the chance?

First, about thyroid. It’s a tiny organ at the base of our neck. It looks like a moth and weighs about 1 tablespoon of butter.

Despite its size, it is a powerful regulator of metabolism, that is, how our body burns energy. Like a general contractor, the thyroid gland oversees most of our body functions.

It produces one hormone. But when it goes wrong, anything can go wrong.

For example, its overproduction – hyperthyroidism – produces symptoms of high metabolism: weight loss, heat intolerance, palpitation, anxiety, loose bowels, tremor, the “eye-popping stare” that Barbara Bush suffered from, etc.

Its underproduction – hypothyroidism – produces fatigue, weight gain, depression, constipation, muscles weakness, hair loss, puffy face, etc. Because these symptoms are common and nonspecific, most of us can tick off at least one from the list. It’s hard to confirm thyroid disease based on symptoms alone.

On the other hand, thyroid production-related (not cancer) disorders are easily diagnosed by blood tests. Thyroid-stimulating Hormone or TSH ($25 to $80) is an excellent first test. If anything, it’s too sensitive and often picks up benign conditions. 

And if the thyroid size is screwy, a thyroid ultrasound is an easy and reliable start ($300 to $1,600).

But just how likely is our weight fluctuation related to thyroid problems?

Globally, thyroid problems are common because of iodine deficiency. An early sign is goiter, where the moth-size thyroid can grow to melon-size. But in the U.S., we have iodized salt, iodine-rich seafood and dairy products. I’ve only seen goiters in immigrants from developing countries.

Our thyroid disorders are likely autoimmune diseases; that is, our immune system is harming our own body. The prevalence of hyperthyroidism in the U.S. is 1 in 100 people; overt hypothyroidism is 1 in 300.

My approach: If I have any doubt, I order a TSH.

Historically, the thyroid taught us important medical lessons.

In the first half of the 20th century, doctors got creative and started to use thyroid hormones to help healthy people lose weight. But the side effects of induced hyperthyroidism could be downright dangerous.

On the other hand, using iodized salt to reduce hypothyroidism is one of the great public health success stories. Our thyroid gland needs iodine to make hormone. Iodine exists mostly in the water and soil of coastal regions. Prior to 1920, the Great Lakes region was part of the “goiter belt,” where 22% to 70% of children had goiters.

In 1905, a young Dr. David Marine, arrived in Cleveland from the East Coast for his pathology residency. He was shocked to see many swollen necks around dogs, people and fish. His study led to the idea of regional dietary iodine deficiency. In 1917, his team gave iodine supplement to thousands of Akron school girls. In years, they brought the incidence of goiter from 1 in 4 girls to 1 in 500 girls. This study led to iodization of table salt.

Public health done right is nothing short of a miracle. To quote the Mandalorian, “This is the way.”