In 2001, Kim Rhyne gained 20 pounds in six weeks. Normally an energetic women’s ministry leader in Cleveland, she was suddenly so exhausted that she could barely drag herself out of bed. “I wasn’t eating a lot more or doing anything any differently than I had been before,” says Kim. “I had no idea what was going on with my body.”
Knowing that an underactive thyroid often causes these symptoms, Kim’s doctor gave her a blood test to check her thyroid function. When the results came back within the normal range—though just barely—he diagnosed her with depression and started her on antidepressants.
Nine months later and not feeling any better, Kim had her thyroid levels rechecked. This time her levels were higher, so her doctor diagnosed her with hypothyroidism and started her on the medication Synthroid, which is commonly used to treat the condition. The drug pushed her test results back into the normal range, but Kim still didn’t feel well. She even struggled to muster up the energy to go grocery shopping or chat with the congregants who frequently stopped by her home. “I would end up in bed before guests even left the house,” she recalls. Meanwhile, she was more irritable than ever, snapping at her husband for the littlest things.
Kim told her doctor how bad she was feeling but he wouldn’t raise her medication dosage, citing her normal test numbers. Then, earlier this year—nine years after she was first diagnosed—Kim started chatting with a woman at church who happened to be an endocrinologist (a doctor trained in the treatment of hormone disorders). The woman suggested that Kim come see her for a workup. Her findings: Kim needed a slightly higher dose of Synthroid. A few weeks later, Kim started to feel like her old self again. “I couldn’t believe that I had spent years feeling tired and irritated when the solution was as simple as taking a little more medication,” says Kim, now 41.
Unfortunately, Kim’s struggle to get the right treatment is not that uncommon. Nearly 13 million people in the U.S. are not correctly diagnosed with hypothyroidism, and experts think that the number is probably climbing. “One in eight Americans is now age 65 or over, and you’re more likely to develop thyroid problems when you get older,” explains E. Chester Ridgway, MD, a professor of medicine at the University of Colorado School of Medicine. “That 13 million may just be the tip of the iceberg,” he says.
Why are thyroid disorders so hard to detect? For one thing, doctors don’t agree on how to interpret screening tests. There are also several tests that check thyroid function, but many doctors use just one. And in some cases, like when test results are borderline “normal,” symptoms should be given extra weight when deciding on treatment.
One Test, Many Interpretations
Your thyroid gland plays a crucial role in regulating just about everything, including your heart rate, metabolism, muscles and mood. If your thyroid is underactive (hypothyroidism), it’s not making enough thyroid hormone, so your body starts pumping out extra thyroid-stimulating hormone (TSH), which makes your TSH levels high. Insufficient amounts of thyroid hormone can cause symptoms like weight gain, fatigue, chills, and dry skin, hair and nails. On the other hand, when your thyroid is making too much thyroid hormone, you’ve got an overactive thyroid (hyperthyroidism), which causes weight loss, insomnia and anxiety.
Although most experts agree that measuring TSH levels with a simple blood test is the best way to detect a thyroid issue, they differ on what should be considered normal. Most primary care doctors use one standard range (0.5 mIU/L to 5.0 mIU/L), but many endocrinologists narrow that range (0.3 mIU/L to 3.0 IU/L), meaning that a larger group of people fall outside it. Kim’s internist considered her TSH levels normal, but her endocrinologist found them high.
It’s also worth noting that the TSH screening isn’t the only one. Doctors can also test for antibodies that show up in Hashimoto’s disease, an autoimmune condition that causes up to 95% of all hypothyroidism cases. It’s possible to have normal TSH levels but high levels of these antibodies, says Theodore C. Friedman, MD, PhD, chief of endocrinology at Charles R. Drew University and a professor of medicine at UCLA. But not all doctors order this additional blood test. Some doctors also believe in measuring two forms of thyroid hormone (T3 and T4).
When Symptoms Matter More
Grace White, 56, had all the classic signs of an underactive thyroid—fatigue, weight gain, hair loss and dry skin. But her TSH was normal, though borderline.
After seeing several doctors, who ruled out other conditions, Grace—who works for an airline manufacturing company in Billings, Montana—saw an endocrinologist. He quizzed her about her symptoms and decided to try her on medication. “Two weeks later I felt so much better,” she says. Today, 16 years later, her endocrinologist still doesn’t go strictly by her blood work. “He always asks how I feel, then decides whether my dose should be adjusted.”
But many doctors aren’t willing to do the same, because the symptoms of hypothyroidism can mimic issues like anemia, type 2 diabetes, sleep deprivation and depression. And no one wants to overtreat, since that can cause cardiovascular problems or osteoporosis.
The results of blood tests almost always determine whether or not you have an underactive or overactive thyroid, but sometimes it makes sense to give symptoms more weight than you would otherwise, says Jeffrey Garber, MD, president-elect of the American College of Endocrinology. In those cases, other health problems must be ruled out, a patient’s TSH must be borderline, and she should have symptoms as well as other signs that point to a thyroid disorder (an abnormal thyroid exam or a family history of the condition). “At that point, I’d consider putting a patient on a low dose of medication and watching her for 6 to 12 weeks,” says Dr. Garber. “If she really has hypothyroidism, she should feel much better.” If there’s no improvement, he’ll stop the treatment.
Getting To the Bottom of It
Since it can be so hard to get the right diagnosis and treatment, you may have to be your own advocate. Some tips that can help:
• Know your TSH number. Most primary care doctors say that a TSH level between 0.5 and 5.0 mIU/L is normal. But many endocrinologists use a narrower, lower range (between 0.3 and 3.0). Note: Endocrinologists are currently debating changing their range to between 0.4 and 4.0.
• See a good endocrinologist. Find one who treats people with a wide range of hormone conditions, including diabetes and adrenal gland problems. (Go to hormone.org.) “Doctors who only see people with thyroid disorders often won’t look for other causes,” says Dr. Friedman.
If your TSH is borderline, ask for a repeat test and an anti-TPO test. TSH levels can fluctuate from day to day. Wait 4 to 6 weeks for a follow-up test, says Leonard Wartofsky, MD, a former president of the Endocrine Society and professor of medicine at Georgetown University. The anti-TPO test will reveal whether you have Hashimoto’s disease.
• Rule out other health conditions. Make sure you also get a blood glucose test for diabetes, a ferritin test for anemia and a mental health screening for depression.
If you have hypothyroidism, taking a thyroid hormone replacement medication is a must. But there are things you can do to help those meds work better, says Dr. Friedman:
Eat foods rich in selenium.
This mineral helps convert thyroid hormone into a form that your cells can use. You’ll find it in Brazil nuts, seeds and grains, chicken, brown rice and eggs. But don’t overdo it if you’re at risk for diabetes—some studies show that selenium raises your risk.
Tell your doctor or pharmacist about any other drugs you take.
Some antidepressants, for example, can affect how much thyroid hormone you need. And blood thinners can become more potent if you’re taking thyroid medication.
Be careful with antacids that contain calcium or aluminum.
They can also block the absorption of thyroid hormone. Wait at least an hour after taking your thyroid meds before you reach for one. (Waiting 4 hours may be even safer, according to the National Institutes of Health.)
Don’t take your thyroid medication at the same time as calcium or iron supplements.
Both nutrients can prevent thyroid hormone from being properly absorbed, so take them at least 1 hour apart.