Women & thyroid disease.

You'd think Judy Pate, 41, would have recognized the symptoms of hyperthyroidism, or Graves' disease, when she developed them last winter. After all, she's been the administrative director at the Thyroid Foundation of America in Boston since March 2005.

But, in a sign of how insidious symptoms of this autoimmune condition can be, it took months before her thyroid was identified as the cause of her problem. At first she attributed her nervousness, tremors and thicker neck to job stress or a virus. But when she started feeling shaky and spent three days on the couch in June, with her heart pounding, feeling as if she had the flu, she finally sought help. Since her diagnosis in June, she's started taking treatment with Tapazole to reduce her thyroid levels and Inderal to slow her heart rate. She is beginning to feel better but still requires treatment. "I'm still shaky, but I'm able to make it to work," she says.

With Graves' disease, your immune system stimulates your thyroid cells to make too much thyroid hormone. With too much of the hormone, your body's metabolism speeds up. Symptoms can be as varied as nervousness, shaky hands, increased sweating, lighter menstrual periods, feelings of being hot all the time, and heart palpitations. Graves' disease accounts for 60 to 80 percent of hyperthyroidism. (17)

Most cases of hypothyroidism occur when the immune system attacks thyroid cells, damaging them so they don't make enough thyroid hormone. It is the most common autoimmune disease in the country. Common symptoms are heavy menstrual bleeding, memory problems, depression, tingling in your hands and feet, weight gain, pounding heart, dry skin, hair loss, brittle nails, always feeling cold, weakness, fatigue, constipation and hoarse voice. (18)

Experts estimate that half of those with hypothyroidism aren't properly diagnosed. That's why the American Thyroid Association recommends measuring blood levels of thyroid-stimulating hormone (TSH) in women every five years beginning at age 35. (19)

The Thyroid Foundation of America would like to see automatic measurements in pregnant women, too, says its founder, Lawrence C. Wood, MD, an internist who practices in the Boston area. "About five percent of pregnant women have hypothyroidism," he says, which can increase the risk of miscarriage, premature delivery, low birth-weight babies and hypertension (toxemia) at delivery. He also recommends that women with a family history of autoimmune diseases have their thyroid hormone levels checked annually.

Treatment for hypothyroidism is relatively straightforward--supplemental thyroid hormone, typically thyroxine. Treatment for hyperthyroidism can be more complex, however, depending on the cause and severity of the disease, age and other medical conditions.

Beta blockers like Inderal (propranolol) are the first-line treatment to help with the fast pulse, tremors and shakiness. Antithyroid drugs that slow the production of thyroid hormone are also commonly used. These include Tapazole (methimazole) and PTU (propylthiouracil). The most common treatment in the United States is radioactive iodine, which is used to damage thyroid cells, so they don't produce so much hormone. Alternatively, doctors may recommend surgery to remove the thyroid gland. Whatever the treatment, sooner or later you will probably need to take synthetic thyroid hormone.

Given the success of treating hyper- and hypothyroidism, Dr. Wood has this advice if you are diagnosed with either: "Don't be nervous. Understand that it's fixable. Consult a physician early and get a second opinion from a thyroid specialist if necessary."

References

17 Ai J, Leonhardt JM, Heymann WR. Autoimmune thyroid diseases: etiology, pathogenesis, and dermatologic manifestations. J Am Acad Dermatol. 2003 May;48(5):641-59; quiz 660-2.

18 Tews MC, Shah SM, Gossain VV. Hypothyroidism: mimicker of common complaints. Emerg Med Clin North Am. 2005 Aug;23(3): 649-67, vii.

19 Ladenson PW, Singer PA, Ain KH et al. American Thyroid Association guidelines for detection of thyroid dysfunction. Arch Intern Med 2000;160: 1573-1575.

20 The American Thyroid Association, ATA Hypothyroidism Booklet. www.thyroid.org. 2003.

RELATED ARTICLE: By the Numbers

You'd think testing for thyroid hormone levels would be relatively simple. It's not. You have two types of thyroid hormone: T4, or thyroxine, and T3, or triiodothyronine. Most screening tests measure T4, which will usually be low if you have hypothyroidism and high if you have hyperthyroidism. But since 99 percent of T4 is bound to carrier proteins that carry the thyroid hormone around in your body, levels constantly change. Thus, the most sensitive test for thyroid function is TSH, which measures a hormone released by your pituitary gland that, in turn, tells your thyroid to release thyroid hormone. Hyperthyroidism is usually diagnosed when TSH levels are below 0.4 mU/L, or milliunits per liter; hypothyroidism is usually diagnosed when levels are above 4.5 mU/L. (5,19,20)