Thyroid Disorders
medical conditions

Thyroid Disorders

Explore the available health information, treatment context, and integrative evidence for Thyroid Disorders.

Background
  • Hormonal disorders or endocrine disorders, including thyroid disorders, are illnesses that occur when the body releases too many or too few hormones. Hormones are chemicals messengers that are released into the bloodstream. Hormones send messages to cells throughout the body in order to regulate bodily functions, such as growth, metabolism, and sexual development. As a result, individuals with hormonal disorders experience a disruption in such bodily functions.
  • Thyroid disorders are among the most common medical conditions but, because their symptoms often appear gradually over time, they are commonly misdiagnosed. There are four main types of thyroid disease: hyperthyroidism or too much thyroid hormone; hypothyroidism or too little thyroid hormone; benign (non-cancerous) thyroid disease; and thyroid cancer.
  • The thyroid gland is a small, butterfly-shaped gland located in the base of the neck on both sides of the lower part of the voice box (larynx) and upper part of the wind pipe (trachea). The thyroid produces hormones, called thyroxine (T4) and triiodothyronine (T3), which affect the body's metabolism and energy level. Thyroid hormone is also produced in response to thyroid stimulating hormone (TSH, also known as thyrotropin) secreted by the pituitary gland.
  • Release of thyroid hormones is controlled by the hypothalamus and pituitary gland, both found deep inside the brain. One of the most important features of the endocrine system is its regulation (control) by negative feedback. This means that the glands that stimulate the release of a hormone (for example, the pituitary) from another gland (for example, the thyroid) are eventually shut off, in a sense, so that too much hormone is not produced.
  • Thyroid disorders affect some 4.5 million Americans. At least 600,000 of them have yet to be diagnosed.
Signs and Symptoms
  • Hypothyroidism: 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.
  • Hyperthyroidism: 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 individuals may also experience lid-lag. This occurs when the eyelids do not move down when the person's eye looks downward.
Diagnosis
  • Blood tests: A blood test that measures the amount of thyroid hormones in the blood is the standard diagnostic test for an underactive thyroid. If the individual has low levels of thyroid hormone in the blood, the patient is diagnosed with hypothyroidism.
  • The levels of thyroxine (T4), triiodothyronine (T3), and thyroid stimulating hormone (TSH) in the blood stream are measured. An overactive thyroid, such as in hyperthyroidism, would be expected to cause high levels of T4 and T3 and low levels of TSH. An underactive thyroid, such as in hypothyroidism, would be expected to cause low levels of T4 and T3 and a high level of TSH.
  • Subclinical hypothyroidism and hyperthyroidism: Some patients are found to have elevated serum thyroid stimulating hormone (TSH) levels, suggesting hypothyroidism, but have normal levels of thyroxine (T4). This state is referred to as subclinical hypothyroidism. Some individuals with subclinical hypothyroidism may have clinical symptoms, such as weakness, lethargy, fatigue, hoarseness, hearing loss, bradycardia (slow heart rate), dry skin, coarse hair, cold intolerance, constipation, weight gain, muscle cramps, and fluid build-up in the eyelids, face, and legs. Treatment of subclinical hypothyroidism is similar to hypothyroidism.
  • Subclinical hyperthyroidism is defined as low serum TSH concentrations in the presence of normal serum thyroid hormone concentrations (T4 or FT4 and T3 or FT3 levels). Individuals with subclinical hyperthyroidism are at increased risk for cardiac arrhythmias and bone loss.
  • Fluorescent antinuclear antibody (FANA) test: The fluorescent antinuclear antibody (FANA) test may be performed to detect abnormal antibodies, called auto antibodies. The auto antibodies bind to components of an individual's own cells and cause the immune system to attack the body. Antibodies are part of the body's immune system defense against foreign substances, such as bacteria and viruses.
  • During the procedure, a small sample of blood is taken from the individual and sent to a laboratory. A scientist adds methyl alcohol to a microscope slide that contains human tissue culture cells. This makes the cells permeable before they are combined with the individual's blood.
  • Then the individual's blood is added to the microscope slide. Fluorescent antibodies that detect the binding of human antibodies to the cells are also added. The scientist uses a fluorescent microscope to view the staining intensity and binding pattern of the cells. If auto antibodies are detected, a positive diagnosis is made for an autoimmune disorder.
  • If an individual has a positive FANA result and has low levels of thyroid hormone in the blood, Hashimoto's thyroiditis is diagnosed.
  • Ultrasound: Ultrasound takes a picture of the inside of the thyroid. Ultrasound bounces sound waves off the thyroid and makes a picture out of the returning echoes. If the ultrasound shows a large mass that is suspicious for cancer, then the doctor can use the ultrasound to guide a needle into the mass to perform a fine needle aspiration biopsy. If there are no large lumps in the thyroid gland that are suspicious for cancer, then no biopsy needs to be done.
  • Nuclear scan: Sometimes a nuclear medicine thyroid scan is ordered to help determine the cause of an individual's overactive thyroid. Individuals swallow capsules that contain a harmless radioactive tracer bound to iodine. Some of this tracer winds up in the thyroid gland. Four, six, or 24 hours after the capsule is ingested (depending on the preferences of the radiology department performing the scan), a scanner is placed over the thyroid gland. This scanner can take a picture of the thyroid gland by detecting the parts of the thyroid gland that have taken up the radioactive tracer.
  • In a normal thyroid gland, radioactive iodine is taken up to the same degree throughout the entire gland. If there is an area of the thyroid that does not take up radioactive iodine well, then it must be further investigated. It can be useful to measure how much of the radioactive tracer wound up in the thyroid gland. This can help determine the cause of the overactive thyroid. However, the actual diagnosis of the overactive thyroid is made with blood tests, not with the scan.
  • Biopsy: Thyroid nodules are fairly common and usually harmless. However, about 4% of nodules are cancerous, so further testing needs to be done. This is usually best accomplished by fine needle aspiration biopsy. This is a quick and simple test that takes just a few minutes to perform in the doctor's office. If the biopsy does not raise any suspicion of cancer, the nodule is usually observed over time to watch for any changes. Some thyroid specialists recommend treatment with thyroid hormone to try to decrease the size of the nodule. A second biopsy is usually recommended six to 12 months later, to make sure there continues to be no evidence of cancer. If a nodule is cancerous, suspicious for cancer, or grows large enough to interfere with swallowing or breathing, surgical removal is advised.
Complications
  • Hypothyroidism
    :
  • General: In general, complications of thyroid disorders develop if the condition is left untreated or if patients do not take their medications or treatments as prescribed.
  • Birth defects: If pregnant women with Hashimoto's thyroiditis do not receive treatment, their babies are more likely to have birth defects. Babies may have intellectual and developmental problems. Researchers have identified a connection between underactive thyroids during pregnancies and brain, heart, and kidney problems in infants.
  • Goiter: When an individual's thyroid is not producing enough hormones, the pituitary gland constantly stimulates the thyroid to release more hormones. As a result, the thyroid may become enlarged, causing the neck to look swollen. This condition is called a goiter. Although goiters generally do not cause pain, a large goiter can 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.
  • Heart problems: If hypothyroidism is not properly treated, individuals may have an increased risk of developing heart disease. The individual's heart may enlarge, and in rare cases, this may lead to heart failure. Researchers have also found a connection between hypothyroidism and high cholesterol. It is unclear why hypothyroidism and subclinical hypothyroidism may lead to high cholesterol levels.
  • Mental functioning: Untreated hypothyroidism may also lead to slowed mental functioning. Individuals may become confused or have trouble thinking or concentrating. Once treatment is started, these symptoms will go away.
  • Mental health: If hypothyroidism is untreated or poorly managed, individuals may suffer from depression. Individuals who are depressed experience sadness, low self-esteem, loss of pleasure, apathy, and sometimes, difficulty functioning. If these problems persist for two weeks or more for unknown reasons, individuals should consult their healthcare providers.
  • Libido: Some males and females may experience a decrease in sexual desire (libido).
  • Myxedema: In rare cases, long-term Hashimoto's thyroiditis that has not been treated may lead to a life-threatening condition called myxedema. This condition causes swelling of the skin and other tissues, especially near the eyes and cheeks. Symptoms may include drowsiness followed by extreme tiredness and unconsciousness due to low levels of thyroid hormone. Patients who experience symptoms of myxedema should seek immediate medical treatment at the emergency department of a nearby hospital.
  • Cretinism: Cretinism is caused by a decreased production of T4 and results in mental retardation, stunted growth, and coarse facial features. The signs of cretinism are constant drooling, a swayback, a potbelly, short stature, and irregularly placed and poorly formed teeth. If this condition is diagnosed within the first several months of life (standard newborn tests should reveal low thyroid levels), the chances of normal development are excellent.
  • Hyperthyroidism
    :
  • Heart conditions: Some of the most serious complications of hyperthyroidism involve the heart. These include tachycardia (rapid heart rate) and congestive heart failure (CHF), a condition in which the heart cannot circulate enough blood to meet the body's needs.
  • Brittle bones: Untreated hyperthyroidism can also lead to weak, brittle bones (osteoporosis). The strength of the bones depends, in part, on the amount of calcium and other minerals they contain. Too much thyroid hormone interferes with the body's ability to incorporate calcium into the bones.
  • Eye conditions: Individuals with Graves' ophthalmopathy develop eye problems, including bulging, red or swollen eyes, sensitivity to light, and blurring or double vision.
  • Skin irritation:
    In rare cases, Graves' disease also affects the skin, causing redness and swelling, often on the shins and feet.
  • Thyrotoxic crisis: Hyperthyroidism also places the individual at risk of thyrotoxic crisis. Thyrotoxic crisis means there is a sudden release of thyroid hormone into the bloodstream, leading to a fever, a rapid pulse, and even delirium. If this occurs, immediately seek medical care.
  • Impaired glucose tolerance (IGT): Individuals with pre-diabetes have blood glucose levels that are higher than normal but not high enough for a diagnosis of diabetes, a condition known as impaired glucose tolerance or IGT. This condition raises the risk of developing type 2 diabetes, heart disease, and stroke. High levels of thyroid hormone, such as in hyperthyroidism, may lead to IGT.
Treatment
  • Hypothyroidism
    :
  • General: Once individuals are diagnosed with hypothyroidism (underactive thyroid) or Hashimoto's thyroiditis, they receive man-made hormones to make up for the decreased hormone levels. Treatment is life-long. Some individuals may need to have their thyroid gland surgically removed. These people will need to take hormones for the rest of their lives, but they are able to live normal, healthy lives.
  • Individuals should tell their healthcare providers if they are taking any other drugs (prescription or over-the-counter), herbs, or supplements because they may interact with treatment. For instance, a cholesterol lowering medication called cholestyramine (Questran®), an ingredient in some antacids called aluminum hydroxide, sodium polystyrene sulfonate (Kayexalate®), an anti-ulcer drug called sucralfate (Carafate®), iron supplements, calcium supplements, and soy may interact with treatment.
  • Thyroid hormone replacement therapy: Individuals usually 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 return to normal functioning. Levothyroxine is the most commonly prescribed thyroid hormone replacement drug. A synthetic form of thyroid hormone, liothyronine (Cytomel®), may also be prescribed. Thyrolar® (Liotrix) is another synthetic thyroid drug that contains both L-triiodothyronine (T3) and levothyroxine sodium (T4).
  • Natural thyroid hormone replacement drugs are made from the desiccated (dried and powdered) thyroid glands of pigs and are available by prescription. Dessicated thyroid drugs have been available since the late 1800s, however since the early 1960s have been largely replaced with use of synthetic levothyroxine. All commercially available brands of desiccated thyroid contain a mixture of thyroid hormones, T4 (thyroxine) and T3 (triiodothyronine). Among the most well known brands of desiccated thyroid in the United States is Armour® Thyroid. Natural thyroid hormone agents are also sometimes called natural thyroid, natural thyroid hormones, pork thyroid, thyroid USP, thyroid extract, or thyroid BP.
  • Individuals should visit their healthcare providers every six to 12 months to monitor their hormone levels. Over time, the dosage may be changed. If the dose is too high, individuals 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, individuals with a history of heart disease, osteoporosis, or severe hypothyroidism may receive smaller doses that are gradually increased over time.
  • Surgery: If an individual patient develops a goiter that does not respond to hormone therapy, the thyroid may need to be surgically removed (called thyroidectomy). Although goiters generally do not cause pain, a large goiter can interfere with swallowing or breathing and it may affect the individual's appearance and self-esteem. Individuals can live long, healthy lives without the thyroid gland. However, they must take hormone pills called levothyroxine (Levothroid®, Levoxyl®, Synthroid® or Unithroid®) for the rest of their lives.
  • Hyperthyroidism
    :
  • Several treatments for hyperthyroidism exist. The best approach depends on age, physical health, and the severity of the condition.
  • Radioactive iodine: Taken by mouth, radioactive iodine is absorbed by the thyroid gland, where it causes the gland to shrink and symptoms to subside, usually within three to six months. Because this treatment causes thyroid activity to slow considerably and for the thyroid gland to shrink in size, individuals may eventually need to take a medication every day to achieve adequate thyroid hormone levels.
  • Anti-thyroid medications: Anti-thyroid medications gradually reduce symptoms of hyperthyroidism by preventing the thyroid gland from producing excess amounts of hormones. They include propylthiouracil (PTU) and methimazole (Tapazole®). Symptoms usually begin to improve in six to 12 weeks, but treatment with anti-thyroid medications typically continues at least a year and often longer. For some individuals, symptoms of hyperthyroidism disappear completely, but others may experience a relapse.
  • Beta blockers: Beta blockers are commonly used to treat hypertension (high blood pressure). They will not reduce thyroid levels, but they can reduce a rapid heart rate and help prevent palpitations. Individuals with hyperthyroidism may be prescribed beta blockers until the thyroid levels are closer to normal and heart symptoms disappear.
  • Surgery: Thyroidectomy is used when the individual cannot tolerate anti-thyroid drugs and does not want to have radioactive iodine therapy, although this is an option in only a few cases. These individuals may be at an increased risk for complications when using drugs or radioactive therapy.
  • In a thyroidectomy, a doctor removes most of the thyroid gland. Risks of this surgery include damage to the vocal cords and parathyroid glands. Parathyroid glands are four tiny glands located on the back of the thyroid gland that help control the level of calcium in the blood. Individuals undergoing a thyroidectomy will need lifelong treatment with levothyroxine (Synthroid®) to supply the body with normal amounts of thyroid hormone. If the parathyroid glands also are removed, individuals will need medication to keep the blood-calcium levels normal.
Prevention
  • The American Thyroid Association recommends that adults be screened for thyroid dysfunction by measurement of the serum thyrotropin (also known as thyroid stimulating hormone or TSH) concentration beginning at age 35 years and every five years thereafter. Individuals with symptoms and signs potentially attributable to thyroid dysfunction and those with risk factors for its development may require more frequent serum thyrotropin testing.
  • Iodine deficiency is the most common cause of hypothyroidism worldwide. Iodine is found in seawater, so any type of seafood is a rich source of this element, particularly seaweed (including kelp, bladderwrack, or dulce). Despite coming from the ocean, sea salt is not a good source of iodine. Iodized salt is perhaps the most common source of iodine in the Western diet and can provide enough iodine to avoid low thyroid activity. Since an adult only requires around one teaspoonful of iodine over a lifetime, eating fish once a week is enough to fulfill the average iodine requirement.
  • The value of dietary iodine can be reduced by vegetables from the brassica family, which includes cabbage, brussels sprouts, raw turnip, broccoli, and cauliflower. In circumstances where both large quantities of these foods are eaten and the levels of dietary iodine are low, goiter could develop.
  • Exercise is important for maintaining healthy hormone levels. Exercise 30 minutes daily, five days a week if possible. A doctor can help design an exercise program that is right for each individual.
References

Natural Standard developed the above evidence-based information based on a thorough systematic review of the available scientific articles. For comprehensive information about alternative and complementary therapies on the professional level, go to www.naturalstandard.com. Selected references are listed below.

  • American Thyroid Association. . Accessed May 6, 2009.
  • Bossowski AT, Reddy V, Perry LA, et al. Clinical and endocrine features and long-term outcome of Graves' disease in early childhood. J Endocrinol Invest. 2007;30(5):388-92.
    View Abstract
  • Centers for Disease Control. . Accessed May 6, 2009.
  • Duntas LH. Oxidants, antioxidants in physical exercise and relation to thyroid function. Horm Metab Res. 2005;37(9):572-6.
    View Abstract
  • The Endocrine Society. . Accessed May 6, 2009.
  • Endocrine and Metabolic Diseases Information Service. . Accessed May 6, 2009.
  • Franklyn JA. Subclinical thyroid disorders - Consequences and implications for treatment. Ann Endocrinol (Paris). 2007; [Epub ahead of print].
    View Abstract
  • Hoang JK, Lee WK, Lee M, et al. US Features of thyroid malignancy: pearls and pitfalls. Radiographics. 2007;27(3):847-60; discussion 861-5.
    View Abstract
  • Kasagi K. Painful Hashimoto's thyroiditis. Intern Med. 2006;45(6):351-2.
    View Abstract
  • Kung AW. Clinical review: Thyrotoxic periodic paralysis: a diagnostic challenge. J Clin Endocrinol Metab. 2006;91(7):2490-5.
    View Abstract
  • Natural Standard: The Authority on Integrative Medicine. . Copyright © 2009. Accessed May 6, 2009.
  • Thyroid Foundation of America. . Accessed May 6, 2009.