Dear Savvy Senior: What are the symptoms of thyroid disease? I’ve been dealing with a number of health issues over the past few years, and a friend of mine recently suggested I get my thyroid checked because it might be causing my problems. — Almost 66

Dear Almost: If your thyroid is out of whack, it can cause a number of health issues that can be tricky to detect because the symptoms often resemble other age-related health problems. In fact, as many as 30 million Americans have some form of thyroid disorder, but more than half aren’t aware of it.

What to know

The thyroid is a small butterfly-shaped gland at the base of your neck that has a huge job. It produces hormones (called T3 and T4) that help regulate the rate of many of your body’s activities, from how quickly you burn calories to how fast your heart beats. It also influences the function of the brain, liver, kidneys and skin.

If the gland is underactive and doesn’t produce enough thyroid hormones, it causes the body’s systems to slow down. If it’s overactive and churns out too much thyroid hormones, it has the opposite effect, speeding up the body’s processes.

The symptoms for an underactive thyroid (also known as hypothyroidism) — the most common thyroid disorder in older adults — will vary but may include fatigue and weakness, unexplained weight gain, increased sensitivity to cold, constipation, joint pain, a puffy face, hoarseness, thinning hair, muscle stiffness, dry skin and depression. Some patients may even develop an enlarged thyroid (goiter) at the base of the neck. However, in older adults, it can cause other symptoms, such as memory impairment, loss of appetite, weight loss, falls and even incontinence.

Symptoms of an overactive thyroid (or hyperthyroidism) could include a rapid heart rate, anxiety, irritability, fatigue, insomnia, increased appetite, weight loss, tremors of the hand, frequent bowel movements, sweating and an enlarged thyroid gland. Hyperthyroidism can also cause atrial fibrillation, affect blood pressure and decrease bone density, which increases the risk of osteoporosis.

Those with the greatest risk of developing thyroid disorders are women who have a family history of the disease. Other factors that can trigger thyroid problems include: autoimmune diseases such as Hashimoto’s or Graves disease; thyroid surgery; radiation treatments to the neck or upper chest; and certain medications including interferon alpha and interleukin-2 cancer medications, amio­darone heart medication and lithium for bipolar disorder.

Get tested

If you have symptoms related to thyroid disease, or if you’ve had previous thyroid problems or notice a lump in the base of your neck, ask your doctor to check your thyroid levels. The TSH (thyroid-stimulating hormone) blood test is used to diagnosis thyroid disorders but depending on what they find, additional blood tests might be necessary.

If you are diagnosed with a thyroid problem, it’s easily treated. Standard treatment for hypothyroidism involves daily use of the synthetic thyroid hormone levothyroxine (Levothroid, Synthroid and others), an oral medication that restores adequate hormone levels.

Hyperthyroidism treatment may include medications such as methimazole and propylthioracil, which block the production of thyroid hormones.

Another option is radioactive iodine, which is taken orally and destroys the overactive thyroid cells and causes the gland to shrink. But this treatment can leave the thyroid unable to produce hormones, which could cause hypothyroidism.

For more information on thyroid disorders, visit the American Thyroid Association at Thyroid.org.

Jim Miller is a contributor to NBC-TV’s “Today” program and author of “The Savvy Senior.” Send your questions to Savvy Senior, P.O. Box 5443, Norman, OK 73070; or visit savvysenior.org.