Unknown: Graves Disease
Unknown: Graves Disease
Graves disease is an autoimmune disorder of the thyroid gland, which means that an abnormal immune response causes the person 's thyroid gland to produce too much of thyroid hormone known as thyroxine. It is named for Robert James Graves (1797–1853), an Irish physician who first described a patient with goiter and exophthalmos in 1835.
In Graves disease, the patient 's thyroid gland, which is located at the base of the throat, is stimulated by an autoimmune response to increase its production of thyroxine. Doctors do not know what triggers the body 's immune system to target the thyroid gland, although some think that genetic factors may be involved. Other researchers think that bacterial or viral infections may trigger the onset of the disorder, as it often appears suddenly, particularly in middle-aged adults. Overproduction of the hormone then causes such characteristic symptoms of the disease as anxiety, general restlessness, sleep problems, bulging eyes, heat sensitivity, and weight loss.
Graves disease is the most common cause of hyperthyroidism in the United States, accounting for 70–80 percent of cases and affecting about
thirty people in every 100,000. It appears to run in some families, with patients often having relatives diagnosed with either Graves disease itself or Hashimoto disease, another thyroid disorder. As of 2008, however, no specific gene had yet been identified as the sole cause of Graves disease.
The disorder is most common in adults over the age of twenty but may affect children as well. It is seven times as common in women than in men. Most affected women are between the ages of thirty and sixty.
Graves disease is found in all races and ethnic groups, but the genetic markers that have been linked to the disorder appear to vary with race and ethnicity.
In Graves disease, a person 's immune system mistakenly produces antibodies that target the thyroid gland; however, instead of destroying the gland, the antibodies stimulate it to make too much thyroxine. Some researchers believe that age and stress may combine with genetic factors to trigger the onset of the disease. In a few cases, Graves disease appears to be triggered by traumatic injury to the thyroid gland.
The most common symptoms of Graves disease are:
- Anxiety, irritable mood, and difficulty sleeping.
- Losing weight in spite of normal or even increased food intake.
Graves Disease and the Bush Presidency
Graves disease is not a communicable disease, and it is rare for it to be diagnosed in a husband and wife within the space of two years. Nonetheless, in the spring and summer of 1991, President George H. W. Bush was diagnosed with Graves disease, only two years after First Lady Barbara Bush had been diagnosed with the same illness.
The President was out jogging one day in May 1991 when he felt a sudden tiredness, shortness of breath, and a rapid irregular heartbeat. He was taken to Bethesda Naval Hospital, where his doctors quickly determined that the problem was in his thyroid gland. He had developed a goiter, had lost nine pounds in the previous two months while eating normally, and had felt unusually tired for the previous two weeks. Bush chose to be treated with radioactive iodine and has taken a replacement thyroid medication ever since.
Barbara Bush had also been treated with radioactive iodine when she was diagnosed with Graves disease in April 1989. The odds that a husband and wife would independently develop Graves disease are thought to be about one in three million. As a result, the doctors who examined the Bushes began to question whether a virus might have been responsible for triggering the disorder in both spouses.
A specialist in thyroid disorders from the Mayo Clinic in Minnesota who was consulted about the case simply described it as a “bizarre coincidence”; it was the only explanation he could think of.
- Exophthalmos. This is a symptom in which the eyeballs bulge outward from the eye socket. This symptom develops because the tissues and muscles behind the eye swell and push the eyeball forward. It is more likely to develop in patients who smoke.
- Goiter. This symptom is an enlargement of the thyroid gland that causes a bulge at the base of the neck.
- Muscle weakness and tremor.
- Brittle hair.
- Increased sensitivity to heat and heavy sweating.
- Speeded-up or irregular heartbeat.
- In women, lighter than normal menstrual periods.
- Frequent bowel movements.
- Double vision and eye irritation.
Undiagnosed and untreated Graves disease can lead to a condition known as thyroid storm, in which the patient 's body temperature rises as high as 105°F (40.5°C). Thyroid storm is a medical emergency and can end in death if not treated. The symptoms of thyroid storm include chest pain, heavy sweating, shortness of breath, disorientation, and very rapid heartbeat as well as a rise in body temperature. The patient should be taken to a hospital for emergency treatment.
Other complications that can result from untreated Graves disease include osteoporosis (brittle bones) and weakened heart muscle leading to congestive heart failure.
People should visit their doctor for a checkup if they notice such outward signs of Graves disease as goiter, weight loss, or increased sensitivity to heat. The doctor will begin by taking a history, including a family history of thyroid disorders. He or she will then check the patient 's eyes for exophthalmos and feel the thyroid gland for swelling. The patient 's blood pressure and pulse will also be checked.
The doctor will then order blood tests to check the levels of thyroxine in the patient 's blood and another hormone known as thyroid-stimulating hormone or TSH. In Graves disease, the thyroid gland is stimulated by an abnormal antibody rather than by TSH, so a blood test that indicates high levels of thyroxine and low levels of TSH points to Graves disease as the cause.
Another test that is used to diagnose Graves disease consists of injecting the patient with radioactive iodine and measuring the amount that is taken up by the thyroid gland. The thyroid gland needs iodine to produce thyroxine, so that if the test shows that the gland is taking up the radioactive iodine in higher amounts, it indicates that the patient has an overactive gland.
There are three major forms of treatment for Graves disease: antithyroid drugs that lower the amount of thyroid hormone produced; radioactive iodine, which destroys all or part of the thyroid gland; and surgical removal of all or part of the thyroid gland. Antithyroid drugs are about 30–50 percent effective in relieving the symptoms of Graves disease and are generally not recommended for younger patients. Radioactive iodine and surgery are 90–95 percent effective, but patients must take replacement thyroid hormone for the remainder of their lives. Radioactive iodine is not recommended, however, for patients with severe eye problems associated with Graves disease.
The prognosis for recovery from Graves disease depends partly on the patient 's overall health and partly on how quickly the disorder is diagnosed. Most patients have good results provided they take replacement thyroid as prescribed and see their doctors for regular follow-up visits. Patients are usually advised to watch for signs of fever, sore throat, and throat ulcers, and see their doctor at once if they develop those symptoms. In most cases of Graves disease, no matter which therapy is used, eventually the patient will wind up with an underactive gland and require replacement thyroid hormone.
There is no known way to prevent Graves disease.
Graves disease is not likely to become more common in the future. It is likely, however, that researchers will discover more information about the genetic factors involved in the disease and the specific conditions that trigger its onset.
SEE ALSO Hashimoto disease; Lupus; Osteoporosis; Rheumatoid arthritis; Sjögren syndrome
WORDS TO KNOW
Autoimmune disorder: A disorder characterized or caused by autoantibodies that attack the cells or organs of the organism producing them.
Exophthalmos: Abnormal protrusion of the eyeballs.
Goiter: A swelling in the neck caused by an enlarged thyroid gland.
Hyperthyroidism: A disease condition in which the thyroid gland produces too much thyroid hormone.
Metabolism: The chemical changes in living cells in which new materials are taken in and energy is provided for vital processes.
Thyroid storm: A medical emergency marked by a rise in body temperature as well as other symptoms caused by untreated hyperthyroidism.
Thyroiditis: Inflammation of the thyroid gland.
Tremor: Trembling or shaking caused by a physical disease.
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Moore, Elaine A. Graves' Disease: A Practical Guide. Jefferson, NC: McFarland and Co., 2001.
Altman, Lawrence K., M.D. “In Strange Twist, Bush Is Suffering from Same Gland Disease As Wife.” New York Times, May 10, 1991. Available online at http://query.nytimes.com/gst/fullpage.html?res=9D0CEED9173CF933A25756C0A967958260&sec=&spon=&pagewanted=all (accessed May 10, 2008).
Mayo Clinic. Graves' Disease. Available online at http://www.mayoclinic.com/health/graves-disease/DS00181 (accessed May 9, 2008).
Medline Plus Medical Encyclopedia. Graves' Disease. Available online at http://www.nlm.nih.gov/medlineplus/ency/article/000358.htm (accessed May 9, 2008).
National Graves ' Disease Foundation (NGDF). What Is Graves' Disease? Available online at http://www.ngdf.org/WhatIs.html (accessed May 9, 2008).