What Is Hypothyroidism and How Do We Treat It?

Nearly one person in every 20 over the age of 12 have hypothyroidism. What is this condition, how do I know if I have it, and how is it treated?

Sabrina Stierwalt, PhD
5-minute read
Episode #296

Fatigue, weight gain, impaired memory...this pretty much describes my life as a parent, but these are also signs of a potential thyroid disorder known as hypothyroidism. Nearly 1 person in every 20 over the age of 12 have hypothyroidism (that’s about 5% of the US population) and most of them are women. Given that the condition can be hard to diagnose and hard to treat, it remains an area of active research.

What Is an Underactive Thyroid?

Your thyroid is a small gland on the front of your neck in the shape of a butterfly that acts as a sort of command system for regulating how your body uses energy. So its function touches on all of our major bodily systems from digestion and reproduction to metabolism, breathing, heart rate, and mood. And when it’s not working right, all of those systems can be affected. In the case of hypothyroidism, the thyroid gland is underactive: it doesn’t produce as much of the thyroid hormones as your body needs.

Could I Have Hypothyroidism?

Rates of hypothyroidism are higher among women and people over the age of 60. Others at higher risk of developing the condition include anyone who has had a thyroid problem before or a family history of thyroid disease, those who have been pregnant in the last six months, and anyone with type 1 diabetes, rheumatoid arthritis, or lupus.

In addition to the fatigue, weight gain, and memory loss already mentioned, other signs you may have hypothyroidism include: feeling cold all the time, joint and muscle pain, constipation, dry skin, reduced sweating, hair loss, fertility problems, depression, high cholesterol, and a slowed heart rate. Since these symptoms usually develop slowly, and since they can often be indicators of other common problems like stress or lack of sleep or just regular old aging, hypothyroidism can easily be left undiagnosed for years.

This broad range of symptoms may seem unrelated but they are all connected under the thyroid’s task of using our body’s energy. For example, an underactive thyroid means a slowdown of your metabolism which can obviously lead to weight gain. But burning fewer calories can also mean you are generating less body heat and as a result, you are colder.

A slowed heart rate also means decreased blood flow which in turn means a slower replenishment of new skin cells. If your old skin cells aren’t replaced, you are left with dry, flaky skin.  

The connections between an underactive thyroid and its nonphysical effects like changes in mood and cognition are less clear, but they could be a result of decreased blood flow to the brain. A lack of the necessary thyroid hormones can also affect the adrenal glands and the brain’s serotonin levels, both of which are linked to issues with depression.

What Causes Hypothyroidism?

There are several different diseases or other factors that can lead to the condition of hypothyroidism. Hypothyroidism is most commonly caused by the autoimmune disorder Hashimoto’s disease where the body’s immune system produces antibodies that attack the thyroid to the point where it cannot make enough hormones. Thyroiditis, or inflammation of the thyroid, can also cause those hormones to leak out rather than being distributed and used properly. Different forms of thyroiditis have different origins, some being autoimmune conditions, and others relating to a virus, while still others are developed postpartum.

Some babies are simply born with a thyroid that is not fully functional, known as congenital hypothyroidism, and of course anyone who has had surgery to remove or radiate part of their thyroid, perhaps as a result of cancer, are at risk of developing an underproductive thyroid.


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About the Author

Sabrina Stierwalt, PhD

Dr Sabrina Stierwalt earned a Ph.D. in Astronomy & Astrophysics from Cornell University and is now a Professor of Physics at Occidental College.