Thyroid problems can lead to a number of conditions, including cardiovascular disease, osteoporosis, and chronic fatigue. But in older adults, thyroid disorders are often overlooked or misdiagnosed, because the symptoms resemble other conditions, says Simeon Margolis, M.D., Ph.D., Medical Editor of our Health After 50 newsletter and Professor of Medicine and Biological Chemistry at Johns Hopkins. Fortunately, tests are available to diagnose thyroid disorders -- and in most cases, effective treatment consists of a simple medication regimen. Here’s what you should know …
Located at the base of your neck below the voice box (larynx), the thyroid is a small, butterfly-shaped gland that is part of the endocrine system. The thyroid makes two iodine-containing hormones -- thyroxine (T4) and triiodothyronine (T3) -- that control metabolism and help organs, like the heart, work properly. But for these functions to be carried out, your thyroid must release an appropriate amount of hormones into the bloodstream -- an activity regulated by the pituitary gland, which produces thyroid-stimulating hormone (TSH), a substance that stimulates the release of both T4 and T3.
When the thyroid overproduces and excessively secretes hormones, this condition is hyperthyroidism (overactive thyroid). The opposite circumstance -- when hormones are insufficiently produced and released -- is hypothyroidism (underactive thyroid). Hypothyroidism causes all of the body’s processes to slow down and may increase heart attack risk because of heightened cholesterol levels.
Many people with hypothyroidism don’t realize they have it. Cold intolerance, fatigue, dry skin or hair, constipation, and muscle cramps are common symptoms -- but simply may be due to aging. An underactive thyroid can also affect brain function, causing memory lapses, which are often just attributed to age-related forgetfulness in older people. Depression and poor mood are other symptoms, as is weight gain. (Although hypothyroidism is commonly thought to be a cause of obesity, in reality hypothyroid patients might gain 5–10 lbs at most.)
The most common cause of hypothyroidism is Hashimoto’s thyroiditis. This disorder of the immune system inflames and scars the thyroid gland, which causes a gradual decrease in the production of thyroid hormones.
If any of these symptoms seem familiar talk to your doctor, who can order blood tests to measure thyroid hormone and TSH levels. Not only can tests help determine if your thyroid is underactive, but measuring TSH can show whether your hypothyroidism is primary (originating in the thyroid) or secondary (originating in the pituitary or the hypothalamus in the brain). The blood tests can also reveal how severe your thyroid hormone deficiency is, and antithyroid antibodies can be measured in the blood to determine whether Hashimoto’s thyroiditis is the cause of your hypothyroidism.
If the diagnosis is hypothyroidism, you will most likely be prescribed synthetic thyroxine (levothyroxine), which is identical to the T4 naturally produced by your thyroid. Thyroxine is available as a generic or brand-name product (for example, Synthroid, Levoxyl, Unithroid, or Levothroid). The medication will normalize hormone levels and is generally taken once a day for the rest of your life.
Should you be tested? Medical opinions vary with regard to how often people should be tested for thyroid disorders, says Dr. Margolis. But as you grow older, it is important to be aware of any changes or emerging symptoms that may signal a problem with your thyroid.
Talk to your doctor about whether to have your thyroid levels checked, especially if you have a family history of thyroid disorders. Some doctors routinely screen their patients for thyroid disease every year.
