Factors That Increase Risk
Anyone can develop thyroid disease, but certain factors make you more likely to develop a thyroid problem than the person who doesn't have that risk. At the same time, having these risk factors doesn't guarantee that you'll have a thyroid problem. Following are some of the main risk factors that can affect thyroid health.
Gender and Age
No doubt, being a woman makes you more vulnerable to thyroid disease. In fact, according to the American Association of Clinical Endocrinologists, one in eight women between the ages of 35 and 65 has thyroid disease, most cases hypothyroidism. And as you age, the risk gets even higher: 20 percent of all women over 65 have thyroid problems.
Being female is also the biggest risk factor for Graves' disease, which afflicts women eight times more often than men. But Graves' is not necessarily a condition of advancing age. Rather, most people develop Graves' disease between ages 20 and 40.
Personal and Family Health History
If you've ever had a problem with your thyroid in the past, your risk for thyroid disease now is higher than normal. For instance, even a brief thyroid problem after pregnancy makes you more vulnerable.
You are also at greater risk for an autoimmune thyroid disease if you have an autoimmune condition such as rheumatoid arthritis, scleroderma, lupus, or psoriasis. Two forms of thyroid disease, Hashimoto's disease and Graves' disease, are also autoimmune illnesses. A discussion of other diseases that might raise your risk for thyroid disorders appears later in this chapter.
The same risk applies to your family members. If a first-degree relative has had or has thyroid disease, then you are more likely to have a thyroid problem. For instance, if your mother had a bout of postpartum thyroid disease after delivery years ago, your risk is slightly higher than someone whose mom didn't have the condition.
But remember, having a personal or family history of thyroid disease or autoimmune disease doesn't mean you will necessarily get thyroid disease. It simply means that your chances of doing so are slightly higher than those of a person who doesn't have that history.
It's safe to say that everyone knows about the toll that cigarettes have on the health of our lungs and hearts. But smoking cigarettes also causes serious problems for the thyroid. In fact, one recent study identified cigarette smoking as a predictor of Graves' disease.
For these reasons — among so many others — people with a personal or family history of thyroid disease or autoimmune illnesses are generally advised not to smoke. And if you find out you do have thyroid disease, do everything you can to quit.
Giving up the cigarette habit is difficult, to say the least. And 21 percent of the U.S. population still lights up despite efforts to nix the habit. The Centers for Disease Control and Prevention offers a listing of useful Internet resources that can help you quit.
Many women will develop thyroid disease during periods of tremendous hormonal shifts, especially during or after pregnancy and just before or during menopause. Approximately 10 percent of all women will develop some form of thyroid disease after pregnancy. In fact, some women will develop a condition called postpartum thyroiditis, an inflammation of the thyroid gland that usually lasts just six to nine months, then disappears on its own. It is often the reason for postpartum depression.
Thyroid disease also occurs around the time of menopause. But because the timing of thyroid disease often coincides with these hormonal shifts, many women go undiagnosed. Patients and physicians alike often assume that their symptoms are related to their reproductive hormones, not their thyroid.
Exposure to Radiation
Say the word Chernobyl, and most people will recall the 1986 nuclear tragedy in Ukraine. One of the subsequent results of that nuclear disaster has been a higher incidence of thyroid disease in the region, including thyroid cancer in children. Studies suggest that exposing the thyroid gland to significant radiation can raise your risk for thyroid disease, including thyroid cancer. However, routine X-rays — as long as you're not pregnant — are unlikely to increase the odds for developing thyroid disease.
What is of concern is radiation done to the head, neck, and throat, such as that used to treat cancers in those parts of the body. For instance, people with Hodgkin's disease who are treated with radiation are at greater risk for thyroid disease. In addition, studies have found that women who undergo multiple X-rays during pregnancy were more likely to give birth to low-weight babies, an effect that the researchers attributed to the probable effect the X-rays had on the thyroid.
Having a Medical Condition
The presence of certain illnesses may actually suggest a thyroid problem. For example, fibromyalgia, a condition characterized by widespread pain and fatigue, and chronic fatigue immune deficiency syndrome (CFIDS), a similar condition marked by persistent and debilitating fatigue, may be due to an undiagnosed thyroid problem and suggest that you need to see an endocrinologist. The same is true if you have an endocrine disorder such as diabetes.
Thyroid problems are also more common in women who have endometriosis, in which the tissue lining of the uterus grows outside the uterus, and in those who have polycystic ovarian syndrome (PCOS), a condition characterized by irregular periods, excess facial and body hair, infertility, and tiny cysts around the ovaries. In addition, thyroid disease is more prevalent in people who have celiac disease, an intolerance of gluten.
The most apparent link between thyroid disease and other conditions occurs in autoimmune problems: people who already have an autoimmune disease, such as lupus, rheumatoid arthritis, or scleroderma, are at increased risk for thyroid disease.
Our modern understanding of the thyroid is relatively recent. In fact, Theodor Kocher, a Swiss surgeon, was the first doctor to remove the thyroid gland for the treatment of goiter. It was Kocher who realized the profound impact of the thyroid on growth and body functions. In 1909, he received a Nobel Prize in medicine for his work on the thyroid gland.
Other Risk Factors
Many people are convinced that other factors are at play in the development of thyroid disease. Some suggest it might be linked to stress. Others suggest it might be the result of a viral or bacterial infection, or the result of physical trauma to the thyroid gland. Even premature graying and being left-handed have been cited as risk factors for thyroid disease.
No single risk factor has been identified as a definite cause for thyroid disease. All we know is that you are more likely to develop thyroid problems if you have one or more of these risk factors.