|
General: The thyroid gland, located in the neck, produces two hormones, called thyroxine and triiodothyronine. These hormones control growth and the rate at which the body uses energy (metabolism). Hyperthyroidism: Hyperthyroidism occurs when the thyroid gland produces too much thyroxine. As a result, the patient's metabolism increases dramatically, causing sudden weight loss and irregular heartbeat. Most patients fully recover from hyperthyroidism with lifelong treatment. However, if left untreated, the condition may be life threatening. Complications may include heart problems, brittle bones, and thyrotoxic crisis (also known as "thyroid storm"). Thyrotoxic crisis occurs when symptoms suddenly become extreme, causing fever, increased heartbeat, and sometimes delirium. The most common cause of hyperthyroidism is Grave's disease. Grave's disease is an autoimmune disorder because it occurs when the immune system mistakenly attacks the thyroid gland, stimulating the gland to produce more hormones. Non-cancerous tumors (abnormal growths) on the thyroid gland may also lead to hyperthyroidism. Some tumors may produce excess thyroid hormone and cause the gland to become enlarged. Hyperthyroidism may also occur if the thyroid gland becomes inflamed. When the gland is swollen, stored thyroid hormone may leak into the bloodstream. Researchers do not know what causes the gland to swell in some patients. Common symptoms of hyperthyroidism include sudden and unexplained weight loss, increased or irregular heartbeat, nervousness, irritability, tremors (especially in the hands), increased sweating, abnormal menstruation, increased sensitivity to warmth, more frequent bowel movements, enlarged thyroid gland (goiter), fatigue, difficulty sleeping, and muscle weakness. Some patients may be unable to close the eyelid (eyelid retraction). Some patients may also experience lid-lag. This occurs when the eyelids do not move down when the patient's eye looks downward. A blood test is the standard diagnostic test for hyperthyroidism. Patients with the condition will have high levels of thyroxine and low or nonexistent levels of thyroid stimulating hormone (TSH) in the blood. There are several treatments available for hyperthyroidism. Patients typically take radioactive iodine by mouth. The thyroid gland absorbs this medication, which stimulates the gland to shrink. Symptoms usually start to improve within three to six months of treatment. However, many patients develop hypothyroidism as a result of radioactive iodine treatment. If hypothyroidism develops, patients need to take thyroxine (Euthyrox ®, Levothroid ®, Levoxyl ®, Synthroid ®, or Unithroid ®) for life. Patients may also medications, such as propylthiouracil or methimazole (Tapazole ®), which reduce the amount of hormones released by the thyroid. Symptoms usually start to improve within six to 12 weeks of treatment. These medications do not cure hyperthyroidism. They are taken to manage symptoms until the underlying cause is treated. Patients generally take these drugs for one year or longer. Surgery is also an option for some patients. During the procedure, most of the gland is removed. As a result, the remaining thyroid gland produces very limited amounts of thyroid hormones. Patients will need to take a man-made version of the thyroid hormone, called levothyroxine (Euthyrox ®, Levothroid ®, Levoxyl ®, Synthroid ®, or Unithroid ®) for the rest of their lives in order to make up for the decreased thyroid gland. Patients may take drugs called beta-blockers to decrease a rapid heartbeat. These medications are used in the short-term, until the hyperthyroidism is successfully treated. Hypothyroidism: Hypothyroidism occurs when the thyroid gland does not produce enough thyroid hormone. A condition called Hashimoto's thyroiditis is the most common cause of hypothyroidism in the United States. Hashimoto's thyroiditis occurs when the patient's immune system attacks the thyroid gland. Researchers have not discovered why the immune system mistakes the thyroid for a harmful invader, such as a virus. It has been suggested that many factors lead to the disorder, including age, heredity, and gender. This is because the condition is most common among middle-aged women. It also common among biological family members. Hypothyroidism may also occur if patients do not consume enough iodine in the diet. This is most common in poor countries where malnutrition is common. Common symptoms of hypothyroidism include sensitivity to cold temperatures, mild weight gain, fatigue, constipation, small thyroid gland, enlarged neck, dry skin, hair loss, muscle cramps, heavy and irregular menstruation, and difficulty thinking or concentrating. Less common symptoms main include facial swelling and joint stiffness. The most obvious sign of severe hypothyroidism is a goiter. A goiter is a severe swelling of the thyroid gland in the front of the neck. Hypothyroidism is diagnosed after a blood test is performed. The test measures the amount of thyroid hormone in the blood. If the patient has low levels of thyroid hormone in the blood, the patient is diagnosed with hypothyroidism. Patients with hypothyroidism receive thyroid hormone replacement therapy with levothyroxine (Levothroid ®, Levoxyl ®, Synthroid ®, or Unithroid ®). This man-made hormone is identical to the natural thyroid hormone called thyroxine. The medication is taken by mouth every day for life to help the body maintain normal functioning. Although goiters generally do not cause pain, a large goiter may interfere with swallowing or breathing and it may affect the patient's appearance and self-esteem. In many cases, goiters will be cured once hormone replacement therapy is started. However, some patients may need to have their goiter surgically removed. Patients should visit their healthcare providers every six to 12 months to monitor their hormone levels. Over time, the dosage may need to be changed. If the dose is too high, patients may develop a condition called osteoporosis, which causes the bones to become hollow and brittle. Also, excessive doses may lead to irregular heartbeats (arrhythmias). In order to prevent complications of overdose, patients with a history of heart disease, osteoporosis, or severe hypothyroidism may receive smaller doses that are gradually increased over time.
 |
Learn
