A Look at Thyroid Disease
Because the signs and symptoms of early thyroid disease can be vague and diffuse, we often attribute them to stress or advancing age. In fact, according to figures from the Thyroid Foundation of America, Inc., approximately 14 million people in the United States suffer some type of thyroid dysfunction. However, more than nine million of these people don't even realize they have thyroid diseases. Are you one of them?
Approximately one in eight women will develop a thyroid problem during her lifetime. In fact, thyroid disease is over seven times more common in women than it is in men. By asking your doctor to perform a simple test, you could be on your way to improving your quality of life.
What Is the Thyroid?
The thyroid gland is a butterfly-shaped gland covering the windpipe just below the Adam's apple in your neck. It is part of the endocrine system, one of the most important systems in the human body. Endocrine glands regulate tissue and organ function, metabolism, and growth and development by secreting thyroid hormones (T4, T3) into the bloodstream. Thyroid hormones regulate cell metabolism (energy production), which affects nearly every organ and cell in the body.
When the thyroid gland produces less hormones than the body needs, the result is ]]>hypothyroidism]]>, the most common form of thyroid dysfunction. When more hormones are produced than necessary, the result is ]]>hyperthyroidism]]>. Timely detection and proper treatment of these conditions allows patients to lead normal active lives. But, left untreated, serious negative health consequences can adversely affect the reproductive system, nervous system, and other major organ systems.
Symptoms of Thyroid Disease
According to the American Association of Clinical Endocrinologists (AACE), symptoms of hypothyroidism may include the following:
- Loss of interest and/or pleasure
- Dry, course hair
- Loss of lateral one-third of eyebrow hair
- Puffy face and eyes
- Goiter (enlarged thyroid gland)
- Slow heartbeat
- Dry skin
- Cold intolerance
- Weight gain
- Heavy menstrual periods
- Brittle nails
- Depressed mood
The AACE's list of hyperthyroidism symptoms may include the following:
- Difficulty sleeping
- Bulging eyes, unblinking stare
- Changes in vision
- Goiter (enlarged thyroid gland)
- Rapid heartbeat
- Increased sweating
- Heat intolerance
- Unexplained weight loss
- Scant menstrual periods
- Frequent bowel movements
- Warm, moist palms
- Fine tremor of the fingers
A Disease That Sneaks Up on You
Thyroid disease, says H. Jack Baskin, MD, past president of the AACE, usually begins in puberty and increases during the teen years, reaching its peak in the 20s and 30s.
"By age 40, it's said that close to 10% of women have a thyroid problem. By age 60, it's more like 15% to 20%," he says. "It can be months or years before a thyroid problem is pinned down as the cause of symptoms."
Dr. Baskin adds that weight loss associated with hyperthyroidism is not as common a symptom as thought, and it is never the only symptom. It is also believed that increased levels of thyroid hormone in the body during the year following pregnancy may be a cause of ]]>postpartum depression]]> in some women.
Many types of thyroid diseases are currently thought to be an “autoimmune disorder” in which the body’s own cells attack (in hypothyroidism) or stimulate (in hyperthyroidism) the thyroid gland. The tendency toward developing either thyroid disorder (hypo or hyper) is commonly hereditary, particularly in females.
"If a mother has it, her daughter has a 25%-50% chance of developing it, although it may not necessarily be the identical disorder," Baskin says. In other words, the daughter of a mother with hypothyroidism may develop hyperthyroidism, or vice versa.
It is also believed that 5%-9% of women develop thyroid disorders following childbirth. They experience transient hyperthyroidism followed by hypothyroidism which may be responsible for a substantial proportion of depression following childbirth.
Not everyone with a thyroid problem experiences the same symptoms. If you are experiencing any combination of the above symptoms, you should specifically ask your doctor to perform a thyroid stimulating hormone (TSH) test. Although this is a particularly sensitive test, it is not as easy as the T4 test, which measures the level of the major thyroid hormone, T4, in the bloodstream.
Dr. Baskin says the T4 test is not as sensitive an indicator of thyroid disease, and people can become quite ill before the T4 test results finally come back abnormal. Results of the T4 test may also be skewed if a person is taking birth control pills or certain medications.
The TSH test is more clinically useful than the T4 test, as it measures the thyroid-stimulating hormone released by the pituitary gland to signal the thyroid to produce hormones. If TSH is high, the thyroid isn't producing enough hormones; the pituitary secretes a lot of TSH to stimulate the thyroid to release more thyroid hormone. If TSH is low, the thyroid is producing too much hormones; the pituitary is telling the thyroid to slow down.
Another advantage of the TSH test is that it can detect thyroid problems much earlier than the T4 test, allowing doctors to institute treatment before symptoms and potential organ damage can occur.
The AACE recommendation states that any woman over the age of 40 be screened periodically with a TSH test. Baskin himself further recommends that the test be performed "at least every two years," and that women with a family history of thyroid disorders be screened every two years after the age of 20 (with a TSH test) and annually after the age of 40.
Treatments for Thyroid Disease
If you are diagnosed with an underactive thyroid (hypothyroidism), normal thyroid levels may be attained by supplementing the body's hormone with a synthetic hormone medication called levothyroxine sodium. This medication is available in tablets and must be taken daily for life. The dosage prescribed by a physician is carefully and gradually adjusted until a normal TSH level has been achieved. The TSH test will have to be repeated periodically (usually during an annual physical, but more frequently at first) to ensure that the dosage continues to be appropriate.
Medication adherence is crucial, as under-replacement of the hormone will not control the symptoms of hypothyroidism and will not prevent potential organ damage. Over-replacement, on the other hand, can cause hyperthyroidism and may put some patients at risk for ]]>osteoporosis]]> and other problems.
If you are diagnosed with hyperthyroidism, the treatment is more complex and can include antithyroid drug therapy (ADT), radioactive iodine treatment, or thyroid surgery. Antithyroid drug therapy for 6 months to 2 years can lead to remission in 4 out of 10 patients. For those who fail to remit, radioactive iodine is the next form of treatment.
While surgery is rarely used today to treat this condition, it may be used in the following conditions: young children, pregnant women who have had a serious reaction to an antithyroid drug, or patients with a large goiter that is causing breathing and/or swallowing problems. A few kinds of hyperthyroid problems may not require treatment, either because they improve on their own or because they aren’t sufficiently severe. Only your doctor can advise you about whether your problem does or does not need treatment.
Remember, if you are experiencing symptoms or have a family history of thyroid disease, don't be afraid to ask your doctor to perform a TSH test. Timely detection and treatment of a thyroid disorder can greatly enhance your quality of life—for the rest of your life.
American Association of Clinical Endocrinologists
The Thyroid Foundation of America, Inc.
Canadian Public Health
The College of Canadian Family Physicians
American Association of Clinical Endocrinologists website. Available at: http://www.aace.com .
Hueston WJ. Treatment of hypothyroidism Am Fam Physician. 2001;64:1717-1724.
Shrier DK, Burman KD. Subclinical hyperthyroidism: controversies in management. Am Fam Physician. 2002;65:431-438
Reid JR, Wheeler SF. Hyperthyroidism: diagnosis and treatment. Am Fam Physician. 2005;72:623-630,635-636.
Wood LC. Thyroid statistics. The Thyroid Foundation of America, Inc. website. Available at: http://www.tsh.org/media/statistics/print . Accessed May 23, 2003.
Last reviewed May 2009 by ]]>Igor Puzanov, MD ]]>
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
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