Thyroid disorders affect up to 20 million Americans, the majority of them women. The most common form, low thyroid function (hypothyroidism) affects women in about 8 of 10 cases. Women of all ages have good reason to educate themselves about thyroid disorders. In a younger woman, a poorly functioning thyroid increases the risk of infertility or of having a child with a birth defect. During menopause, a sick thyroid may contribute to a list of troubling symptoms such as hot flashes and excessive menstrual flow. And in later life, thyroid disease is frequently a factor in high cholesterol, heart disease, rhythm abnormalities and osteoporosis. From 10 to 20 percent of American women are troubled by thyroid disease at some time in their lives, and many of these problems go undetected.
Types of thyroid problems
When your thyroid is underactive or working more slowly in producing the hormones that regulate metabolism, you have hypothyroidism (hypo=low). The reverse condition, an overactive thyroid, is hyperthyroidism (hyper=high).
So important is the work of the thyroid that any aberration can lead to an array of physical and mental changes, ranging from grey hair and bags under the eyes to changes in sex drive and mood. By the same token, these symptoms are so intertwined with aging that it’s hard to separate them from the normal ups and downs of life.
Obese persons like to believe that they have a “slow metabolism.” Actually, that is rarely the case. Although a person with hypothyroidism is vulnerable to weight gain, it’s usually only a few extra pounds, most of which is due to water retention.
Other physical signs such as fatigue, chills, dry skin, coarse hair, heavy periods, swelling and puffiness around the face and eyes are fairly common for anyone over age 40. And it’s also easy to overlook the slowed mental functioning, poor concentration and forgetfulness that come with an underactive thyroid; or the anxiety, nervousness and insomnia that are hallmarks of an overactive one.
Low thyroid function can be difficult to recognize since it tends to develop slowly and many of the symptoms are vague and overlap with other conditions associated with aging and menopause. Some more unusual consequences of thyroid disorders include signs of carpal tunnel syndrome, hoarseness, depression, difficulty coping with the cold, and personality change.
Women between the ages of 40 and 60 are at highest risk of low thyroid function. It can also affect younger women who should be carefully monitored and treated during pregnancy. Of the 20 million Americans believed to have thyroid disease, more than 60 percent do not know and may never know they have it unless they are screened.
Too much thyroid hormone circulating in the blood leads to hyperthyroidism, or overactive thyroid, a condition that creates many of the opposite effects to low thyroid function. Symptoms include weight loss, vision problems, diarrhea, heartbeat irregularities, light menstrual flow, sensitivity to heat, excessive sweating and tremor.
Screening for thyroid problems
Screening today can be done with a simple blood test measuring blood levels of TSH (thyroid stimulating hormone). When the thyroid is sluggish, the pituitary increases production of TSH. This helps spur greater thyroid production, even before symptoms start appearing. Thus an elevated TSH means a low thyroid level, hypothyroidism. Simple screening tests for low thyroid are now available at Bremo Pharmacy. For a small fee, a few drops of blood can determine if a serious low thyroid problem exists. Further evaluation by the physician is then warranted.
The American Thyroid Association recommends screening once every five years for all Americans over age 35 and then once every five years. More frequent testing is recommended for persons with risk factors. The American Thyroid Association advocates screening, stating that “if only patients presenting with clearly suggestive symptoms and signs are evaluated, many affected individuals will remain undiagnosed.” The U.S. Preventive Services Task Force, on the other hand, recommends a more conservative approach by waiting until symptoms or problems occur before screening is done.
The arguments in favor of screening early are strongest for pregnant women and those who have just given birth; women over 50; and both men and women age 60 and over. These are the groups most likely to develop thyroid problems and most vulnerable to the potential complications.
Hyperthyroidism can also be detected with TSH laboratory tests. Overactive thyroid is often treated with radioiodine ablation or surgery to reduce or completely remove the thyroid gland. After these procedures, many patients must take thyroid supplements to maintain normal blood levels.
Because symptoms of thyroid disease are often vague, testing is an effective strategy.
Risk factors
The risk factors for developing thyroid disease include:
- previous thyroid problem
- goiter,
- surgery or radiotherapy affecting the thyroid
- diabetes,
- pernicious anemia,
- loss of skin pigment (or vitiligo),
- prematurely gray hair
- family history of thyroid disease or adrenal insufficiency.
A recent study found smoking associated with an increased risk of developing thyroid disease. The greatest risk for smokers, according to the study, was for developing two types of thyroid disorders, Graves disease and autoimmune thyroiditis.
The importance of treatment
There’s little agreement among doctors or medical groups as to whether to screen for thyroid disorders and, when testing is done, the criteria for starting treatment. “Normal” levels of TSH (thyroid stimulating hormone) are generally considered to be between 0.5 and 5.0 milliunits/liter, but the American Association of Clinical Endocrinologists recommended in 2003 that doctors consider treatment when readings are higher than 3.0.
A panel of experts evaluating existing research reported in January of 2004 [Journal of the American Medical Association] that there is “no compelling evidence” to treat patients with slightly elevated readings–between 4.5 and 10.0–even in those with symptoms. Some medical groups and doctors dissented vigorously and published a rebuttal in January, 2005.
Some experts believe that detection and early treatment of thyroid problems in older women could reduce the incidence of high cholesterol, atherosclerosis and heart attacks. It could also prevent myxedema–a rare but often life threatening condition that sometimes occurs late in life due to an extremely underactive thyroid.
Undiagnosed hyperthyroidism increases the risk of atrial fibrillation (an abnormal heart rhythm) and osteoporosis. These can also occur with over-treatment, and that is one reason for the caution taken in the U.S. Preventive Services reluctance to endorse widespread screening.
Thyroid hormones play a role in the normal function of the ovaries. As a result, a woman with abnormal thyroid function may experience irregular menstrual periods, difficulty getting pregnant and an increased potential for miscarriages, preeclampsia and other problems during pregnancy. Treatment of thyroid problems can reduce menstrual irregularities and is often used as one strategy to improve fertility.
In practice, most women are not screened. That’s why it’s important to educate yourself about the thyroid.
An individual taking thyroid replacement medications such as levothyroxine should be aware of possible interactions with other drugs or herbal supplements.
A healthy thyroid is essential to overall physical wellbeing and normal function of many of the body’s organs. If you’re experiencing symptoms of either high or low thyroid function, especially if you’re a woman between 40 and 60, talk to your doctor about a TSH test. If a problem exists, effective treatment options are available.
2008
Michelle Herbert Thomas, PharmD, CDE
Clinical Director, Richmond Apothecaries, Inc.
