Thyroid Disease Often Goes Unrecognized
Brenda Blackburn had been feeling more tired than she could ever remember. At first, the 50-year-old Harford County, Md., woman attributed the debilitating fatigue to her diabetes, but it only got worse. Finally she couldn’t walk up and down stairs without weakness and exhaustion.
Her physician, endocrinologist James Mersey, tested her thyroid, the gland responsible for regulating the body’s metabolism, to determine how well it was functioning. The results surprised her: “He told me it was literally dead!”
After several months of taking thyroid hormone replacement medication--a regimen that continues for life--Blackburn regained her normal level of energy. And she began to realize that other physical changes she had noticed in recent years--such as thinning hair--were also due to an underactive thyroid rather than to aging or menopause.
Blackburn’s misunderstanding of her symptoms is common. Although an estimated 22 million Americans have some form of thyroid disease, perhaps as many as a third do not even realize they are affected, according to the Thyroid Society for Education and Research in Houston.
The thyroid gland, located in the neck below the Adam’s apple, is responsible for controlling the rate at which the body uses energy for its various chemical processes. Autoimmune disorders, surgery and radiation can cause the thyroid to malfunction, either slowing down the body or speeding it up, to unhealthy levels.
Like autoimmune disorders in general, thyroid disorders are far more common in women than in men. Studies show that by the age of 65, more than 10% of U.S. women have an underactive thyroid, a condition known as hypothyroidism. This disorder can be very hard to recognize, doctors say, because the constellation of symptoms that signal sluggish metabolism can also suggest other conditions, such as depression.
Because hypothyroidism is so common, the American College of Physicians and the American Society of Internal Medicine recommend routine screening for thyroid function in women 50 and older.
“A lot of hypothyroidism goes unnoticed because the symptoms seem nonspecific and are gradual in onset,” says Dr. Paul Ladenson, an endocrinologist at Johns Hopkins Hospital. “People chalk them up to life stress. Or they just think, ‘Oh well, I’m getting older.’ ”
General Signs
According to the Thyroid Society, symptoms of hypothyroidism can include feeling slow or tired; feeling cold; feeling drowsy during the day even after sleeping all night; having a slow heart rate of less than 60 beats a minute; elevated blood pressure; poor memory; difficulty concentrating; muscle cramps and numb arms and legs; weight gain; husky, hoarse voice; puffy face, especially under the eyes; thinning hair; dry, coarse, flaky yellowish skin; constipation; heavy menstrual flow; infertility; and goiter, an abnormal swelling in the neck.
The most common cause of hypothyroidism is Hashimoto’s thyroiditis, an autoimmune disease that causes the body to produce antibodies that damage the thyroid gland. No one knows yet what triggers this condition, but it occurs in families and is eight times more likely to affect women. Hypothyroidism often develops so slowly that people don’t realize they have it until, like Blackburn or Olympic athlete Carl Lewis, they discover it through a blood test.
If left untreated, however, hypothyroidism can cause infertility, miscarriage, anemia, even coma. Treatment is usually simple: A pill taken daily, usually for the rest of a person’s life. (Thyroxine, the thyroid hormone replacement medication, ranges from about $35 to $50 for a three-month supply of 90 pills.) Dosages should be reevaluated each year.
People at greater risk for underactive thyroid are those with a relative who has the condition, those who have an autoimmune disorder such as Type 1 diabetes, and those who have had radiation therapy to the head and neck.
Another common thyroid disorder is hyperthyroidism, or overactive thyroid--a condition that affects nearly 2.5 million Americans, many of them women age 20 to 40.
Hyperthyroidism causes the body’s processes to speed up abnormally, sometimes leading to heart palpitations and trembling hands. Other symptoms of an overactive thyroid include fast heartbeat (more than 100 beats per minute); slightly elevated blood pressure; increased sweating; shakiness; nervousness; difficulty sleeping; weight loss in spite of a good appetite; muscle weakness (particularly in the shoulders, hips and thighs); fingernails partially separated from fingertips; swollen fingertips; retracted upper eyelids; increased frequency of bowel movements; goiter; decreased menstrual flow; and, in men, slight swelling of the breasts.
In addition, individuals with Graves’ disease, the most common form of hyperthyroidism, may notice the skin over their shinbones thickening or swelling, or find that their eyes appear to be popping out of their sockets.
If left untreated, hyperthyroidism can ultimately cause psychosis, life-threatening irregular heartbeat and shock. This autoimmune disease is usually treated by reducing thyroid function with an oral dose of radioactive iodine. The medication makes many patients become hypothyroid, eventually leading them to take the same daily thyroid replacement pills as people with underactive thyroids.
Side effects to thyroid medication occur only if a patient takes too much of it, says Ladenson. There are no allergic reactions or organ damage from the proper dosage. But too much medication can cause bone loss in women, especially after menopause, and a fast, irregular heartbeat in people older than 60.
Such factors as age, weight and pregnancy can affect dosages. And some medications, such as iron supplements, can interfere with thyroxine absorption.
Riskier for Kids
Unlike adults, however, children may suffer irreversible damage if they are not quickly diagnosed and treated. The discovery that roughly one in 4,000 children is born with an underactive thyroid, which can cause severe mental retardation, for instance, has prompted routine screening of newborns.
It is common for children who develop the condition before adolescence to have goiters and delayed growth.
Other signs are general puffiness, delayed dental development and precocious puberty. Sometimes, school performance deteriorates. However, many children with underactive thyroids also do well in school, Ladenson says, because although they are slow, they are not easily distracted--and they behave themselves.
With hyperthyroidism, on the other hand, grades can plummet immediately. Kids who begin to show other symptoms, such as hyperactivity and emotional outbursts, can be mistakenly sent to counselors or psychiatrists to check for an attention or hyperactivity disorder.
In the elderly, thyroid disorders are often overlooked as well. According to the Thyroid Society, older patients with overactive thyroids may not develop goiters or complain of heat intolerance or nervousness as younger people do. They may also lose their appetite, which masks the reason for their weight loss.
Physicians say that certain physical clues point to a greater likelihood of an autoimmune thyroid disorder. They include premature graying of the hair (before age 30); insulin-dependent diabetes or pernicious anemia (caused by lack of vitamin B-12); patchy hair loss; or vitiligo, the appearance of harmless white spots on the skin.
Sometimes people are disappointed to find out that they don’t have a thyroid disorder. Although hypothyroidism frequently appears in middle age, it’s not usually responsible for midlifers’ most often-expressed health concerns, says Mersey, an endocrinologist at Greater Baltimore Medical Center.
“The single most common complaint we hear from people between the age of 40 and 55 is weight gain and not having enough energy,” Mersey says. “And the great majority of those people don’t have a thyroid problem.”
