Mood Disorders

Tired? Depressed? Check Your Thyroid


By Paula Dranov
Condensed from American Health (May '94)

When This Gland Goes Haywire, Watch Out

Julie Amato of Simsbury, Conn., had been a high-energy person. "I ran five to seven miles a day and was always the one to say 'Go, go, go.'"

But things changed after the birth of her first child, and Amato, 35, felt "horrible. My hands and feet were always cold. My periods were much heavier, and I had so little energy that just getting up the stairs was a major effort. I thought I was dying."

Finally she saw a doctor "who took one look at me and said, 'It's your thyroid.'" A blood test confirmed Amato was hypothyroid - her thyroid gland was underactive, producing too little thyroid hormone. With daily treatment her energy level has gradually increased."

Ann Maltz, 37, of Houston was also a new mother. "I was jittery, my hair was falling out, I wasn't sleeping and my heart seemed to be racing," she remembers. Like Amato - and many other women - Maltz blamed the stress of motherhood.

One day, while she was going downstairs, her legs slid out from under her. She was too weak to stand. From the swollen appearance of her neck, Maltz's physician suspected a thyroid problem. Tests confirmed it: Her thyroid was on fast-forward, producing too much hormone. Maltz now feels fine after treatment for hyperthyroidism.

"AFTER diabetes, thyroid disease is the most common glandular disorder," says Dr. Martin Surks, head of endocrinology at New York City's Montefiore Hospital. At least 11 million North Americans - one million of them Canadians - are being treated for thyroid conditions, usually an underactive (hypo-) or overactive (hyper-) gland.

Because some early symptoms are easily ignored or mistaken for signs of anxiety disorders or aging, millions of cases of thyroid disease remain undiagnosed. "Some patients go from doctor to doctor for years complaining of irritability, heart palpitations, difficulty concentrating, even memory problems, before they finally get help," says neuropsychologist Robert Stern, director of neurobehavioural research at Rhode Island Hospital in Providence.

Women are four times as likely as men to develop thyroid problems, probably because they're more prone to the malfunction that underlies the majority of cases. Essentially, their immune systems, failing to recognize the thyroid gland as part of the body, send antibodies to attack it.

The thyroid is a small, butterfly-shaped gland located at the base of the neck over the trachea, or windpipe. Its job is to extract iodine from blood to produce two hormones - thyroxine and triiodothyronine - that regulate the energy use of virtually every cell and organ in the body. When your thyroid becomes underactive or overactive, here's what to watch for - and do.

UNDERACTIVE glands are twice as prevalent as overactive ones. The most common cause of hypothyroidism is an autoimmune disorder called Hashimoto's disease, named for the Japanese physician who first recognized it in 1912.

In addition, five to eight percent of women develop hypothyroidism soon after giving birth. While this pregnancy-related condition is usually temporary and often doesn't require treatment, some new mothers may need to take thyroid hormone indefinitely.

Radiation therapy to the head or neck, pituitary tumours, or certain drugs, such as lithium for psychiatric ailments and the heart drug amiodarone (Cordarone), can also lead to hypothyroidism.

Whatever the cause, an underactive thyroid leaves the body running in slow motion. Changes may include fatigue, feeling cold, diminished concentration and memory, and weight gain.

In time the symptoms become worse: dry skin and brittle nails, constipation, muscle aches or cramps, slow heart rate and, in women, longer menstrual periods with heavier flow. Because the disease brings about irregular ovulation, untreated women may have trouble conceiving and have a higher-than-normal rate of miscarriage and premature delivery.

Depression also results from hypothyroidism. Up to 20 percent of all chronic-depression cases may be associated with low production of thyroid hormones. A University of North Carolina study found that among women with mildly decreased thyroid function, the rate of those who had suffered depression at least once in their lives was almost three times as great (56 percent versus 20 percent) as among those with normal thyroid function. Often, unfortunately, patients who are treated for depression do not first get thyroid tests.

There's no way to cure an underactive thyroid, but treatment can be as simple as a pill-a-day lifetime hormone replacement. Determining the right medication and dose, though, may require experimenting. Too much thyroid hormone increases risk of bone loss, osteoporosis and cardiac arrhythmia; too little can lead to mild high blood pressure and elevated cholesterol levels.

Sometimes treatment for an underactive thyroid may even create the symptoms of hyperthyroidism and vice versa. A San Jose, Calif., woman was told she had Hashimoto's disease, and a synthetic thyroid hormone was prescribed. "One day," she says, "my heart started racing and my head was pounding. I thought I was having a stroke." It turned out that the dose was too high and brought on symptoms of hyperthyroidism. Now that her dosage has been adjusted, she is fine.

"Even a small medication mistake may have consequences, especially if you become hypothyroid at 25 or 30 and aren't checked at least yearly to make sure the dose is right," says endocrinologist Reed Larsen, chief of the thyroid division at Boston's Brigham and Women's Hospital.

The main cause of an overactive gland is another autoimmune disorder, Graves' disease, named for the 19th-century Irish physician who was one of the first to describe it.

Symptoms are the flip side of hypothyroidism: rapid heartbeat, nervousness and irritability, feeling hot, muscle weakness, softening of the nails, hair loss, more frequent bowel movements, weight loss despite eating as usual, and, for women, shorter menstrual periods with lighter flow. Although some Graves' patients feel supercharged and wired, they may at the same time feel weak and wiped out.

Many people affected by hyperthyroidism also develop eye problems, including redness, irritation, dryness or swelling. For a small percentage of patients, symptoms include increased pressure on the optic nerve or tissue buildup behind the eyes, causing bulging from the sockets. "It's like having size-ten eyes in size-seven sockets," says Nancy Patterson, executive director of the U.S. National Graves' Disease Foundation.

Treating an overactive thyroid can also be tricky. There are three alternatives: radioactive iodine to disable the gland, drugs to turn off excess hormone production, or surgery to remove the thyroid, followed by hormone replacement. Most doctors recommend radioactive iodine. For about 90 percent of patients, this treatment also involves the use of thyroid hormones to bring levels back to normal.

Since Graves' disease can go into remission, a doctor may decide to try other drugs instead. In about five percent of cases, however, the medications cause side effects, including a rash, low-grade fever or joint aches.

Surgery is usually reserved for hyperthyroid patients who have a large, disfiguring goiter (enlargement of the thyroid) that is not likely to shrink with other treatment and, in some cases, for women with the condition who are either pregnant or who plan to become pregnant. Although the operation is generally safe, there's a small risk of injury to the parathyroid glands (four tiny glands adjacent to the thyroid) or vocal cords.

Blood tests can diagnose thyroid disorders. The most sensitive test measures thyroid-stimulating hormone (TSH), secreted by the pituitary gland. When the thyroid is underactive, TSH levels will be high; low TSH levels signal an overactive thyroid.

A proper thyroid test measures both TSH and the principal thyroid hormone, thyroxine. There are also blood tests for the antibodies found in Hashimoto's and Graves' diseases.

Unless you have a thyroid nodule - a distinct lump on an otherwise normal gland - further testing may not be necessary. Although thyroid cancer is rare (about 1,100 Canadian cases a year), a nodule might be cancerous, and for this reason a scan, sonogram or biopsy is appropriate. A history of radiation exposure, especially to the head or neck, is a primary risk factor for thyroid cancer.


To get more information on thyroid disease, contact The Thyroid Foundation of Canada, 1040 Gardiner Road, Suite C, Kingston, Ont., K7P 1R7 or call 1-800-267-8822.

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