Thyroid Ailments Hard to Recognize

Shelly, 39, who loved to ride her horse, could barely summon the energy to get out of bed, let alone get to the stable. She used to work out and lift weights, but suddenly she was exhausted all the time, and felt sick.

She thought perhaps she was just getting older, but she knew that wasn't right, since she ate right and worked out.

"This thing is so insidious," she says.

She was diagnosed with everything from the flu to chronic fatigue syndrome to depression. Finally, after several months of barely being able to function, a simple blood test revealed the problem -- thyroid disease.

Now she's back riding again, and lifting weights.

To say that thyroid disease goes undiagnosed is an understatement. Millions of Americans suffer from this easily treated disease without knowing it, in part because the symptoms are so vague.

The American Association of Clinical Endocrinologists (AACE) has launched a campaign titled, "Hiding in Plain Sight: Thyroid Undercover" to increase awareness about thyroid disease.

In November 2002, the AACE announced new guidelines for what are considered the normal ranges for thyroid levels.

Thyroid function is measured with a simple blood test called TSH, thyroid stimulating hormone. Previously, a normal result was thought to be anything between 0.5 and 5, but, explains Hossein Gharib, M.D., F.A.C.E, a professor of medicine at the Mayo Medical School and president of the AACE, studies in the past few years suggest the range is actually much narrower: 0.3 to 3.

"We are not suggesting everybody outside of that range needs to be treated," Gharib says. "But 95 percent of the population falls within that range, and 0.3 to 3 should be the target range for people on medication."

The thyroid is a butterfly-shaped gland in the neck that produces hormones that impact on every cell and tissue in the body, influencing vital tissues in the heart, muscles and central nervous systems, among others. It is almost like a carburetor, setting the "idle speed" of the body.

"If your thyroid isn't working, then your body isn't working," Gharib says.

The thyroid probably isn't working enough for millions of Americans. In the Colorado Study, 30,000 people were randomly interviewed and tested at fairs in that state. Some 10 percent of those older than 60 were found to have abnormal TSH ranges.

Why is the disease so hard to diagnose?

The symptoms are vague: Those with an underactive thyroid complain of weight gain, fatigue, lethargy, feeling cold and constipation. An overactive thyroid causes weight loss, diarrhea, tremor, feelings of anxiousness and nervousness, and fatigue.

"Most of these are very non-specific," Gharib says. "It's easy to say, 'Oh this is part of being nervous or growing old.' "

Although the disease is more common in women, it does strike men, too, particularly elderly men. Gharib notes that 5 percent to 10 percent of elderly women suffer from thyroid disease, compared to 1 percent to 4 percent of elderly men.

Various organizations have offered different guidelines for when to screen, and what are considered normal levels, which is another reason why there is confusion about getting diagnosed. But as Gharib points out, the test is simple, reliable and widely available.

The AACE recommends screening all newborns, and anyone taking drugs that can affect the thyroid such as lithium, used to treat bipolar disorder, or amiodarone, used for heart arrhythmias. Everyone else should undergo periodic screening.

Eighty percent of those diagnosed with thyroid disease have an underactive thyroid, which is easily treated by taking a levothyroxine sodium pill once a day. Mild cases of thyroid disease can be treated by a primary care physician, but endocrinologists are needed if the patient is under 18, pregnant, unresponsive to therapy, a cardiac patient, or if they have a goiter, nodule or other structural changes in the thyroid or another endocrine disease.

A TSH level below the 0.3 mark, indicates overactive thyroid, and it could mean that patients on thyroid medication are getting too much. Anything over a level of 3 indicates an underactive thyroid, although Gharib says there is considerable disagreement as to when treatment needs to be initiated. Some internists and endocrinologists do not treat patients with levels between 5 and 10, opting instead to carefully monitor those patients.

But everyone wants to prevent clear-cut cases of thyroid disease from going undiagnosed. In the case of Shelly, the equestrian, her TSH level was 10. But after six weeks on medication, she felt marked improvement.

"We want to bring this to the attention of the public because it can be easily diagnosed and easily treated," Gharib says.

External Source American Association of Clinical Endocrinologists

This article was reviewed and updated June 2007.

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