Treatment for hyperthyroidism may involve antithyroid medication or radioactive iodine treatment (a one-time pill), depending on your doctor’s recommendations. Surgery may be an option, depending on your health. People successfully treated for an overactive thyroid sometimes develop an underactive one. “Someone with hyperthyroidism might have symptoms that seem more typical of hypothyroidism,” Pinkstaff says.
Hypothyroidism
Hypothyroidism occurs when the thyroid gland stops producing enough thyroid hormone. The incidence of hypothyroidism increases with age. By age 60, as many as 17% of women and 9% of men have an underactive thyroid. Hypothyroidism is treated by taking the thyroid hormone in pill form.
The symptoms of hypothyroidism can be nonspecific. “People with hypothyroidism might feel tired, bloated, cold, constipated, or they may have a depressed mood or forgetfulness,” Surks says. “Hypothyroidism’s onset can be so gradual, people may barely notice the symptoms,” Pinkstaff adds.
It’s important to treat a severely malfunctioning thyroid. While most people may not give much thought to this little gland, a malfunctioning thyroid can have significant health consequences.
Thyroid disease and other health conditions
Fluctuating thyroid levels can adversely affect your heart, especially if you already have any type of heart disease. “Conditions like angina, heart failure, or rhythm disturbances can worsen with thyroid disease,” Surks says. Pinkstaff adds, “With hyperthyroidism, osteoporosis can worsen. And if your muscles are weak, you can be at an increased risk for falls.”
“Other common conditions that can be caused or aggravated by thyroid disease are depression or anxiety,” says Mark Holden, M.D., Erickson Health physician at Eagle’s Trace, an Erickson-built and -managed community in Houston, Tex.
Important medication considerations
“Medications for hyperthyroidism, like propylthiouracil or methimazole, can suppress the immune system,” Holden says. “It’s not a common side effect, but it’s a serious one. If you’re taking one of these drugs and you develop a fever, sore throat, or any other sign of infection, you need to contact your health care provider right away.”
Levothyroxine is also commonly prescribed for hypothyroidism. “The main problem with this drug is getting the dose just right,” says Surks. Holden adds, “Antacids, and other medications that change the acid balance in your stomach, can affect the way levothyroxine is absorbed.” Some foods, like soy and high-fiber products, may also affect absorption.
Since absorption of levothyroxine can vary, you should tell your doctor if your pharmacy changes your medication from a brand name (Synthroid, Levothroid, Levoxyl) to the generic, or if your pharmacy changes generic manufacturers. If your medication changes, your doctor may recommend a blood test after a few months to make sure your thyroid hormone levels are stable.
A different type of hypothyroidism
Many older adults who have no symptoms are diagnosed with hypothyroidism simply through a routine annual blood test. Their actual thyroid hormone levels (T4) might be normal, but they have mildly elevated levels of thyroid stimulating hormone (TSH)—a condition known as subclinical hypothyroidism.
“Surveys have shown that up to 10% or 15% of people in their 70s and 80s have subclinical hypothyroidism,” Surks says. “It’s also been shown, however, that up to half of people with subclinical hypothyroidism will have normal TSH levels after a period of time without any treatment. So it’s not unreasonable for you to ask for a recheck of your blood work prior to starting a medication that you’ll be taking for the rest of your life.”