Women should have routine thyroid tests every five years beginning at age 35, according to Lewis Braverman, MD, chief of endocrinology at Boston University Medical Center. A TSH test runs anywhere from $20 to $80 and is covered by most health insurance plans. There's another, less common test called the TRH test that some doctors and alternative practitioners prefer, believing it offers a more accurate way to diagnose subtle thyroid dysfunction. It's expensive, though, and few doctors use it because they feel the TSH test is just as good. One or the other should be administered to the following:

• Women of all ages who have unexplained aches and pains, intolerance of cold, hair loss, sleep troubles, fatigue, dry skin, constipation, weight gain, forgetfulness, or heavy periods.
• Men with those symptoms (minus the heavy periods). Although women are up to ten times more likely to have thyroid troubles, men are not immune.
• Anyone with high cholesterol.
• Women who are depressed, even mildly.
• Women who have trouble conceiving or have suffered a miscarriage.
• Women who have recently had a baby or are entering menopause. Thyroid disease is often triggered during times of hormonal change.
• Women with a family history of thyroid disorders or other autoimmune diseases.