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When your thyroid gland malfunctions

Created date

May 14th, 2019
This drawing of the human body shows the thyroid gland lit up in red.

Did you know?

The primary risk factor for thyroid disease is having a family history. 

Source: National Institutes of Health

Your thyroid gland is a small, butterfly-shaped gland that sits above your collarbone. You probably don’t give much thought to the health of your thyroid, like you do about heart health, but you might be surprised at how much it affects your bodily systems. Its main job is to produce hormones that regulate your heart, breathing, digestion, and bodily temperature.

Older adults are at risk of developing thyroid problems, simply because of the aging process. According to the American Thyroid Association (ATA), the likelihood of thyroid disease increases after age 60, and up to 25% of older adults may be affected.

The most common conditions are when the gland is underactive (hypothyroidism), overactive (hyperthyroidism), or when thyroid gland nodules develop.

Hypothyroidism

“The most common reason for hypothyroidism is the body’s own antibodies attacking the thyroid gland,” says Kenneth Burman M.D., section director of Endocrinology at MedStar Washington Hospital Center in Washington, D.C. “It is an autoimmune response, but we do not know why it begins.”

Radiation treatment for cancer of the head, neck, or chest can also cause hypothyroidism.

Symptoms may be hard to detect or they may seem nonspecific. “People may notice fatigue, slower speech, memory problems, dry skin, or constipation,” Burman says. “People tend to cite weight gain as a major sign of hypothyroidism, but among older adults, weight gain is typically minimal.”

Treatment is fairly straightforward. “Most patients are successfully treated with pure synthetic levothyroxine,” Burman says. “It is considered safe and effective, unlike some other forms of thyroid hormone.”

These other forms of hormone are advertised as “natural” because they are derived from animals such as cows or pigs. Common generic names include nonsynthetic thyroid hormone, desiccated thyroid, or levothyroxine-liothyronine (porcine) thyroid hormone. Brand names include Armour Thyroid, Nature Throid, Westhroid, NP Throid, and WP Thyroid. According to the ATA, nonsynthetic thyroid is rarely prescribed, and there is not enough scientific evidence to support its superiority over synthetic levothyroxine.

“The levels of hormone in these preparations can fluctuate greatly and may be dangerous,” Burman adds.

The American Geriatrics Society Beers Criteria for Potentially Inappropriate Medication Use in Older Adults has listed desiccated thyroid compounds as potentially harmful for older patients because of possible adverse effects on the heart.   

Hyperthyroidism

“Some symptoms of hyperthyroidism, such as nervousness, hand tremors, inability to concentrate, enlarged eyes, or weight loss, tend to be seen in younger adults rather than seniors,”

Burman says.

A common sign in older adults, however, is atrial fibrillation. “Up to 10% of atrial fibrillation is due to an overactive thyroid,” Burman says. “Atrial fibrillation often manifests as palpitations.”

A condition called Graves’ disease, also an autoimmune process, is a common reason for hyperthyroidism in seniors. “The presence of nodules can also cause the secretion of excess hormone, as can someone inadvertently taking too much medication for an underactive thyroid,” Burman says.

Treatment includes medication (commonly methimazole), surgery to remove the thyroid gland, or radioactive iodine. These treatments, however, render the thyroid gland underactive or completely inactive, and most people will need to start taking levothyroxine.

Nodules

“Some studies show that 40% to 60% of seniors have thyroid nodules,” Burman says. “Most are noncancerous. We don’t know for sure why they occur, although they can be associated with antibodies or radiation.”

Nodules usually don’t cause symptoms. “They tend to be found incidentally, such as during a physical examination, or a patient may notice it themselves,” Burman says. “Sometimes a diagnostic test for another condition will reveal nodules.

“If nodules are a certain size, we will test some of the cells for cancer,” Burman continues. “In 90% to 95% of cases, they are benign, in which case we monitor them for changes. If they are cancerous, the standard treatment is surgery.”

Detecting thyroid disease

With the tendency toward subtle symptoms in older adults, a thyroid problem may not be detected at all. Screening for thyroid problems does not tend to be part of a regular physical examination either. “Most professional associations, including the ATA, do not recommend screening for thyroid disease unless someone has symptoms,” Burman says.

In addition, tests may be inaccurate in some people, especially if they are in the hospital. “Thyroid function tests are most accurate in people who are fairly healthy,” Burman says. “People with multiple chronic conditions or who are taking multiple medications may be misdiagnosed because thyroid values in the blood may be affected by these circumstances.”

Regardless, you should report symptoms of any type to your regular doctor, especially if something has changed physically, and ask about screening. “It is easy to make sure your thyroid gland is healthy,” Burman says. “It takes a simple blood test, and most thyroid problems are easily treated.”

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