One evening about five years ago, I sat on the floor, back against my bed, and stared aimlessly at the wall for an hour.

One evening about five years ago, I sat on the floor, back against my bed, and stared aimlessly at the wall for an hour.

Over the course of a particularly stressful year, I had been feeling progressively more tired, without much energy or motivation, and even found myself frequently depressed — something I had never experienced before.

I knew it was time to get help.

As it turns out, I was among the one in 10 Americans who suffer from thyroid disease. This exceeds the number of diabetes and cancer patients combined, yet half of thyroid disease sufferers remain undiagnosed, according to the American Association of Clinical Endocrinologists (AACE).

"Fatigue, feeling suddenly older in a short period of time, is a typical symptom of hypothyroidism. But you need to interpret these symptoms in context. Other things can make you tired," says Dr. James Theen, a Medford endocrinologist.

The butterfly-shaped thyroid gland at the base of the neck is the endocrine gland that controls your metabolism, so when it's underactive — a condition known as hypothyroidism — you will often feel tired, sluggish and depressed. Other common symptoms include weight gain, dry skin, brittle and thinning hair, constipation and cold intolerance.

Other, less common symptoms help Ruch family-practice doctor Andrew Watson confirm a diagnosis of hypothyroidism.

"I sometimes see a slight anemia, also tendonitis. The body is not repairing tissues as quickly because the thyroid controls metabolic activity," says Dr. Watson.

Diagnosing an underactive or overactive thyroid includes a blood test and is most often performed by primary-care doctors. The key indicator is the level of thyroid-stimulating hormone, or TSH. If your TSH value is below the normal range, your thyroid is overactive. Above the range, and it's underactive.

A blood test revealed that my TSH was above normal, and the doctor prescribed thyroid hormone replacement.

For several months, I tried to improve my condition with diet. My research indicated that eating iodine-rich foods might help. But I felt even worse, and a subsequent blood test revealed that my TSH had risen again.

In addition to checking TSH, many doctors look at blood tests for "free T4" and "free T3," as well. T4 is the hormone produced by the thyroid gland, and T3 is the form that hormone ultimately takes when absorbed by the body.

Seeking a holistic remedy, I visited a naturopath who prescribed Armor Thyroid, an extract of the thyroid glands of pigs and cows, used widely 50 years ago, but not so common today. It works well for some patients. I found some relief of my symptoms, but not consistently.

I ultimately consulted a specialist — an endocrinologist — who prescribed a combination of T4 and T3. This has worked well for the past four years, though a mild form of my former symptoms returns occasionally.

Treatment is often complicated by foods that interfere with thyroid hormones. In her book, "Living Well With Hypothyroidism," national patient advocate Mary Shomon chronicled medical studies that found that soybean consumption interferes with iodine uptake. Iodine is a key element in thyroid hormones.

On Shomon's Web site,, she recommends taking thyroid medication on an empty stomach to maximize absorption of thyroid medication. She also highlights studies that have found that both caffeine and cigarettes interfere with healthy thyroid function.

An overactive thyroid — hyperthyroidism — is just as dangerous as an underactive thyroid if untreated for a long time. Although both an underactive and an overactive thyroid cause fatigue, many symptoms of an overactive thyroid are just the opposite: weight loss, diarrhea, moist skin, constantly feeling hot.

The overactive hyperthyroid condition is more difficult to treat and involves trying to block the excess thyroid hormone. In extreme cases, part of the thyroid gland is removed surgically. Limiting iodine in the diet is often the first line of defense. Spinach, kelp and seafood are rich in iodine.

For all types of thyroid disease, says Theen, the best approach is to "eat right and exercise, live your life in a way that's consistent with general health principles."

Simple. Inexpensive. It seems to be working for me.