Our hearts, brains, livers, kidneys, and skin all rely on one tiny, often-overlooked, butterfly-shaped gland: our thyroid. Located just under our voice box, this little workhorse regulates several body functions and plays a huge role in metabolism — if we need more energy, for example, it pumps out more hormones to deliver it. When we were young, it was also a major driver of our growth and development.
Most of us have likely never given it a second thought - unless you've already had a thyroid condition. And the fact is, 20 million Americans today have some form of thyroid dysfunction or disease. Women are particularly affected, accounting for five to eight times more cases than men. The good news is that most of these conditions are fairly easy to treat. The bad news is that up to 60% of people with thyroid problems are unaware that we have them — and undiagnosed disorders of the thyroid gland put us at risk for a number of serious conditions.
January is National Thyroid Awareness month, making this the perfect time to gain a better understanding of how the thyroid works, identify the symptoms of common thyroid-related issues and diseases and learn about testing and treatment options. This blog will provide an overview of the thyroid gland, explain how it works to regulate many of our bodies' vital functions, and list common symptoms of thyroid dysfunction.
What Is the Thyroid Gland?
The thyroid gland is a butterfly-shaped endocrine gland normally located in the lower front of the neck. The thyroid's job is to make hormones that are secreted into the blood and then carried to every tissue in the body. The thyroid hormone helps the body use energy, stay warm, and keep the brain, heart, muscles, and other organs working as they should.
How does the Thyroid Gland Work?
The primary thyroid hormone secreted by the thyroid gland is called T4 because it contains four iodine atoms. To exert its effects, T4 is converted to T3 by the removal of an iodine atom. This occurs mainly in the liver and in certain tissues where T3 acts, such as in the brain. The amount of T4 produced by the thyroid gland is controlled by another hormone, which is made in the pituitary gland located at the base of the brain, called thyroid stimulating hormone (abbreviated TSH).
The amount of TSH that the pituitary sends into the bloodstream depends on the amount of T4 that the pituitary sees. For example, if the pituitary sees very little T4, then it produces more TSH to tell the thyroid gland to produce more T4. Once the T4 in the bloodstream goes above a certain level, the pituitary's production of TSH is shut off.
This seems very complicated, but it's not. Consider the thyroid and pituitary acting like a heater and a thermostat. When the heater (thyroid gland) is off and it becomes cold, the thermostat (pituitary gland) reads the temperature and turns on the heater. When the heat rises to an appropriate level, the thermostat senses this and turns off the heater. Thus, the thyroid and the pituitary, like a heater and thermostat, turn on and off. This feedback loop keeps the levels of T4 in the blood stable and reacts to small changes immediately.
What Happens if it Stops Working Correctly?
Typically the thyroid gland produces the exact number of hormones needed to keep the body's metabolism running and in balance. As described earlier, the TSH secreted by the pituitary gland remains constant in blood circulation, but its levels may increase or decrease when T4 levels in the blood change. However, several disorders are associated with the thyroid gland with most problems concerning the production of thyroid hormones. Either the thyroid gland produces too much hormone (called hyperthyroidism) or your thyroid doesn't produce enough hormone (called hypothyroidism), resulting in your body using energy faster or slower than it should.
Signs You May Need a Thyroid Gland Examination
If you're experiencing any of the following symptoms, it may be time to get your thyroid checked:
Mood ChangesSymptoms of hyperthyroidism may include anxiety, nervousness, and irritability, while symptoms of hypothyroidism may include depression.
Changes in SleepHyperthyroidism can cause difficulty falling asleep at night, which can lead to fatigue, while the lack of thyroxine in hypothyroidism can drain your energy. Both hypo & hyperthyroidism can also cause muscle weakness, leading to feelings of tiredness.
Difficulty Regulating TemperatureHyperthyroidism can cause sensitivity to heat and excessive sweating, while hypothyroidism can lead to difficulty keeping warm. The changes in hormone levels associated with thyroid disease can confuse the body into producing too much heat and not enough energy or the other way around.
Missed Period (Without Pregnancy)Thyroid issues can lead to a missed period due to the disruption of hormones caused by thyroid dysfunction. Too much or too little of the hormone thyroxine can cause an abnormal menstrual cycle or even a complete cessation of menstruation. When this happens, it's referred to as hypothyroid amenorrhea. This condition is usually associated with other signs and symptoms, such as fatigue, weight gain, hair loss, dry skin, constipation, and decreased libido.
Significant Weight Changes (With No Change in Routine)Too much or too little of the hormone thyroxine can cause an abnormally slow metabolism, resulting in difficulty losing or gaining weight. This can result in either rapid and unexpected weight gain or rapid and unexpected weight loss.
Take Care of Your Health
As you can see, thyroid disease can have serious health implications and it's important to recognize the symptoms of poor thyroid function.
If you experience fatigue, abrupt weight changes, or any of the other aforementioned symptoms, it's important to see a doctor to be evaluated and possibly tested for thyroid disease. With early diagnosis and treatment, you can protect your long-term health and well-being.
Editor's Note: This blog was originally published on 1/01/2021 and was updated on 1/30/2023.