Hypothyroidism Research Paper
NURSING ADULTS II
HYPOTHYROIDISM
NAME
SCHOOL
TABLE OF CONTENTS
INTRODUCTION 3
ANATOMY AND PATHOPHYSIOLOGY 3
SIGNS AND SYMPTOMS 7
RISK FACTORS 8
DIAGNOSTIC MEASURES 9
TREATMENT 10
RECENT DEVELOPMENTS 11
COMPLICATIONS 12
BIBLIOGRAPHIES 17 Introduction
This document aims to provide you with a comprehensive overview of a thyroid disease called Hypothyroidism. Section one will discuss the anatomy and pathophysiology of the disease to show its common causes and what specific parts of the body are affected. The next section will detail how hypothyroidism is detected and the possible complications that may arise if it is left untreated. Treatment procedures will be highlighted in succeeding section including preparations, …show more content…
possible complications or side effects and medications that are usually given to patients with this type of disease. After which, literature on some of the most recent developments involving treatment, devices, research into causative factors and the like will be presented. The psychosocial aspects of the disease will also be discussed briefly and some recommendations on where else to locate new information about the disease process will be indicated. It should be noted that this document is by no means a prescriptive form of information. It does not intend to replace professional opinion nor serve as a substitute. If you experience any of the symptoms of hypothyroidism, it is still best to seek help from your doctor or health center.
Anatomy and Pathophysiology
As mentioned, Hypothyroidism is a disease of the thyroid, a gland which regulates the body's metabolism, heart rate, blood pressure, and body temperature, among other functions. It is a butterfly-shaped gland located at the base of your neck, just below your Adam's apple (please see Annex A for an image of the thyroid gland). Although it weighs less than an ounce, the thyroid gland has an enormous effect on your health (Mayo clinic, 2004). In fact, a variety of disorders can plague it, including autoimmune disorders, benign and malignant tumors, and goiter (an enlargement of the thyroid that may be caused by either over- or under-production of thyroid hormone) (Brown, V. Disrupting a delicate balance: environmental effects on the thyroid, 2003).
In order to produce your thyroid's two principal products--thyroxine (T4) and triiodothyronine (T-3), together known as the "thyroid hormone", the body utilizes an element called Iodine. This hormone maintains the rate at which your body uses fats and carbohydrates, burn calories, help regulate your body temperature, influence your heart rate and help in controlling the production of protein. Your thyroid gland also produces calcitonin, a hormone that regulates the amount of calcium in your blood.
The rate at which thyroxine and triiodothyronine are released is controlled by your pituitary gland and your hypothalamus an area at the base of your brain that acts as a thermostat for your whole system. First, the hypothalamus signals the pituitary gland to produce a hormone called thyroid-stimulating hormone (TSH). TSH signals the thyroid gland itself to capture iodine from the blood to synthesize, store, and release T-4. Once T-4 has reached an adequate circulating level, the hypothalamus and pituitary reduce their output of Thyroid Releasing Hormone (TRH) and TSH until the T-4 level again drops. [T.sub.4] circulates in the blood both freely and bound to carrier proteins. When T-4 finally reaches the cells, it is converted to T-3 which is actually the biologically active form. T-3 can alsoe released by the thyroid and can stick to carrier proteins.
Sometimes, the thyroid fails to produce enough hormones. The Mayo Clinic (2004) provides a comprehensive list of possible causes for this condition:
Autoimmune disease (Hashimoto's thyroiditis). Autoimmune disorders occur when your immune system produces antibodies that attack your own tissues. Sometimes this process occurs within the thyroid gland. Scientists aren't sure why the body produces antibodies against itself. Some think a virus or bacteria might trigger the response, while others believe a genetic flaw may be involved. Most likely, autoimmune diseases result from more than one factor. But however it happens, these antibodies affect the thyroid's ability to produce hormones.
Treatment with radioactive iodine. The most common treatment for people who produce too much thyroid hormone (hyperthyroidism) is radioactive iodine. The radioactive material becomes concentrated in the thyroid gland, reducing its function. Often, however, function is reduced too much, resulting in hypothyroidism. Anti-thyroid drugs such as methimazole (Tapazole) also used to treat conditions in which the thyroid produces too much thyroid hormone may cause hypothyroidism as well.
Radiation therapy. Radiation used to treat cancers of the head and neck can affect your thyroid gland and may lead to hypothyroidism.
Thyroid surgery. Removing all or a large portion of your thyroid can diminish or halt hormone production. In that case, you'll need to take thyroid hormones for life.
Medications. A number of medications can contribute to hypothyroidism. One of the most common is lithium, which is used to treat certain psychiatric disorders. If you're taking medication, ask your doctor about its effect on your thyroid gland.
Less often, hypothyroidism may result from one of the following:
Congenital disease. Approximately one in 3,000 babies in the United States is born with a defective thyroid gland or no thyroid gland at all. In most cases, the thyroid gland didn't develop normally for unknown reasons, but some children have an inherited form of the disorder. Often, infants with congenital hypothyroidism appear normal at birth. That's one reason why doctors now recommend that all newborns receive thyroid tests when they're between 24 and 72 hours old.
Pituitary disorder. About 1 percent of cases of hypothyroidism are caused by the failure of the pituitary gland to produce enough TSH usually due to a benign tumor of the pituitary gland.
Pregnancy. Some women develop hypothyroidism during or after pregnancy (postpartum hypothyroidism), often because they produce antibodies to their own thyroid gland. Left untreated, hypothyroidism increases the risk of miscarriage, premature delivery and preeclampsia a condition that causes a significant rise in a woman's blood pressure during the last three months of pregnancy. It can also seriously affect the developing fetus.
Iodine deficiency.
The trace mineral iodine found primarily in seafood, seaweed, plants grown in iodine-rich soil and iodized salt is essential for the production of thyroid hormones. Before the 1920s, it wasn't unusual for people to develop hypothyroidism because they consumed too little of this mineral. But the addition of iodine to table salt has virtually eliminated this problem in the United States. In other parts of the world, however, as many as 200 million people may have iodine deficiencies.
The World Health Organization (WHO) estimates that 740 million people worldwide suffer from iodine deficiency--the most common cause of preventable thyroid disease and mental retardation in the world--and only about 57% of people in the developing world consume iodized salt, the primary means of correcting iodine deficiency. Iodine deficiency is common in inland areas of the world where people do not have access to iodine-rich foods such as ocean fish, kelp, and sea salt, or where they consume foods that interfere with the body's uptake of iodine (Brown, …show more content…
2003).
Diet can also interfere in various ways with the optimum operation of the thyroid gland (Dobson, The Iodine Factor in Health and Evolution, 1998). Apart from a failure to consume foods containing iodides, iodine deficiency diseases and disorders such as hypothyroidism can occur from the excessive intake of goitrogens, substances that prevent the use of iodine by the thyroid. These include maize, sweet potato, cabbage, cassava, kale, groundnuts, soybeans, turnips, and the seeds of cabbage, mustard, and rape (Matovinovic, G. J. Endemic Goitre and Cretinism at the Dawn of the Third Millennium. 1983). Apart from these dietary goitrogens, hard water has also been found to cause endemic goiter, both in humans and in animals used in experiments. Although hard water may contain more iodine than does soft water, goiter is widespread in hard-water regions (Foster, H. Commentary: Neandertals and the Thyroid Gland; the Selenium Connection, 2002).
Signs and Symptoms
The symptoms of hypothyroidism are mainly dependent on the amount of decrease in thyroid hormone and duration of time that the decrease has been present. For most patients, the symptoms are mild and can often be confused with other problems. At first, you may barely notice symptoms such as fatigue and sluggishness, or you may simply attribute them to getting older. But as your metabolism continues to slow, you may develop more obvious signs and symptoms, including the following (New York Thyroid Center, Hypothyroidism, 2005):
· fatigue and muscle swelling or cramps (mainly in the arms and legs)
· tingling in the fingers
· loss of equilibrium
· weight gain
· dry skin and cold intolerance
· yellow skin
· coarseness or loss of hair
· goiter (enlarged thyroid causing a lump in the neck)
· constipation
· hoarseness
· memory and mental impairment
· decreased concentration
· depression
· irregular or heavy menstruation
· infertility or miscarriages
· slowed heart rate
· myxedema: fluid infiltration of the tissues causing puffiness (mainly in the face)
Risk Factors
Although anyone can develop hypothyroidism, it occurs mainly in women older than 40, and the risk of developing the disorder increases with age. You also have an increased risk if you:
· Have a close relative, such as a parent or grandparent, with an autoimmune disease
· Have diabetes, which moderately increases the risk that you'll develop hypothyroidism during or after pregnancy
· Have been treated with radioactive iodine or anti-thyroid medications
· Received radiation to your neck or upper chest, even if the treatment occurred years ago
· Have had thyroid surgery (thyroidectomy) (Mayo Clinic, 2004)
Recent studies show that a mother's thyroid hormone has direct impacts on her baby's brain development. Congenital hypothyroidism may result from lack of thyroid hormone late in pregnancy and the first months of a child's life. If untreated, this condition results in moderate to severe mental retardation, growth failure, deafness, and neurological problems. Those symptoms can be ameliorated by administering synthetic thyroid hormone before the child is three months old. After that, it's too late--the defects are permanent (Renner, R. New thyroid theory: how maternal hormone affects developing brains, 2003).
Diagnostic Measures
When hypothyroidism is suspected, your doctor bases the diagnosis on your symptoms and blood tests that measure the amount of thyroxine and TSH circulating in the blood. A low level of thyroxine are indications that the thyroid is underactive (Zamula, E. Many Treatments Available: Thyroid Disorders Often Unsuspected, 1992).
In the past, doctors weren't able to detect hypothyroidism until symptoms were fairly advanced. Now, they use the sensitive TSH test, which enable them to diagnose thyroid disorders much earlier even before you experience the symptoms. Since the TSH test is the best screening test, your doctor will likely check TSH first and follow with a thyroid hormone test if needed. TSH tests also play an important role in managing hypothyroidism by helping your determine the right dosage of medication, both at the onset and in the long run. In addition, TSH tests are used to help diagnose a condition called subclinical hypothyroidism, which usually manifests no outward signs or symptoms. In this condition, you have normal blood levels of T-3 and T-4, but higher than normal levels of TSH.
Treatment
Hypothyroidism is usually treated with the synthetic drug thyroxine.
Since it mimics the action of natural thyroid hormone, it has very few side-effects. However, if the dose is too high, symptoms of hyperthyroidism can occur such as intolerance of hot temperature, excessive sweating, weight loss, anxiety and insomnia to name a few. Other side-effects are muscle weakness, abnormal heart beats and chest pain. If you do experience side-effects it is certainly worth discussing them with your doctor (Briscoe, J., M.D., Mercury 2: What Are Results of Thyroid Trouble, 2005) MERCURY MEDIC..
Some doctors may prefer Amour Thyroid that contains natural thyroid hormones. Natural hormones also have T1 and T2 in addition to T3 and T4. Armour thyroid is a natural desiccated thyroid. It was the only available treatment for hypothyroidism for some 50 years. Because of concern about their variable potency, these extracts have been considered obsolete for some time by all but a few natural prescribers (Lam, M. M.D., Hypothyroidism,
2004).
While synthetic thyroid hormone made in the laboratory by drug companies usually contain T3 (Cytomel) and T4 (levothyroxine) or combinations (Thyrolar) of these two. Patients with hypothyroidism show greater improvements in mood and brain function if they receive treatment Armour thyroid rather than Synthroid (thyroxin). Some studies found that a majority of patients, however, might feel better on a combination of hormones such as combination of T3 and T4 instead of single T4 alone (Lam, 2004).
Therapy for hypothyroidism should be monitored at approximately 6 week intervals until stable. During visits, a blood sample is checked for TSH to determine if the appropriate amount of thyroid replacement is being given. The goal is to maintain the TSH within normal limits. Depending on the lab used, the absolute values may vary, but in general, a normal TSH range is between 0.5 to 5.0uIU/ml. Once stable, the TSH can be checked yearly. Over-treating hypothyroidism with excessive thyroid medication is potentially harmful and can cause problems with heart palpitations and blood pressure control and can also contribute to osteoporosis. Every effort should be made to keep the TSH within the normal range (Medicine.net, 2005).
Levothyroxine causes virtually no side effects when used in the appropriate dose and is relatively inexpensive. If you change brands, let your doctor know to ensure you're still receiving the right dosage. Also, don't skip doses or stop taking the drug because you're feeling better. If you do, the symptoms of hypothyroidism will gradually return. People with hypothyroidism need to take medication for the rest of their lives.
Certain medications, supplements and even some foods may affect your ability to absorb levothyroxine. Talk to your doctor if you eat large amounts of soy products or a high-fiber diet or you take any of the following (Mayo Clinic):
Iron supplements
Cholestyramine (Questran)
Aluminum hydroxide, which is found in some antacids
Sodium polystyrene sulfonate (Kayexalate)
Sucralfate
Recent Developments
A recent interesting finding showed that women treated for hypothyroidism had less tendency to develop primary breast cancer and more likely to have more indolent disease when they did develop breast cancer than women with normal thyroid function. In this study, women with primary hypothyroidism were found to have had a 61% lower risk of developing invasive breast cancer, and women with breast cancer were 57% less likely to have hypothyroidism, compared with healthy women. This finding strengthens the possibility of thyroid hormones as having a significant role in the treatment of breast cancer (Kilgore, C. Retrospective study shows hypothyroidism tied to lower breast Cancer risk, 2005).
Complications
When hypothyroidism isn't treated, symptoms can gradually become more severe. Constant stimulation of your thyroid to release more hormones may lead to an enlarged thyroid (goiter). In addition, you may become more forgetful, your thought processes may slow or you may feel depressed (Mayo Clinic, 2004).
Another complication of severe and long-standing hypothyroidism is called myxedema. If you have this disorder, you may become very cold and drowsy, and may eventually lapse into a coma. Uncommon in tropical climates, this rare condition may be brought on by cold weather, infection, or the use of some drags, especially sedatives. About 50 to 60 percent of people with hypothyrnid coma die. FDA approved Triostat (liothyronine sodium), an intravenous thyroid hormone replacement drug for the treatment of myxedema coma and pre-coma, in 1991 (Zamula, 1992).
Other complications are:
Heart problems. Hypothyroidism may also be associated with an increased risk of heart disease, primarily because high levels of low-density lipoprotein (LDL) cholesterol the "bad" cholesterol can occur in people with an underactive thyroid. Even subclinical hypothyroidism, a more benign condition than true hypothyroidism can cause an increase in total cholesterol levels and impair the pumping ability of your heart. Hypothyroidism can also lead to an enlarged heart.
Mental health issues. Depression may occur early in hypothyroidism and may become more severe over time. Hypothyroidism can also cause decreased sexual desire (libido) in both men and women and can lead to slowed mental functioning.
Myxedema. This rare, life-threatening condition is the result of long-term, undiagnosed hypothyroidism. Its symptoms include intense cold intolerance and drowsiness followed by profound lethargy and unconsciousness. A myxedema coma may be triggered by sedatives, infection or other stress on your body. If you have symptoms of myxedema, you need immediate emergency medical treatment.
Birth defects. Babies born to women with untreated thyroid disease may have a higher risk of birth defects than do babies born to healthy mothers. Doctors have long known that these children are more prone to intellectual and developmental problems, but recent studies also show a link between hypothyroid pregnancies and birth defects such as cleft palate. A connection also exists between hypothyroid pregnancies and heart, brain and kidney problems.
Infants with untreated congenital hypothyroidism are also at risk of serious problems with both physical and mental development. But if the condition is diagnosed within the first few months of life, the chances of normal development are excellent (Mayo Clinic, 2004).
Psychosocial Aspect
Hypothyroidism may affect your social behavior when you begin to feel the more evident symptoms, especially those that have to do with mood changes. As mentioned, among the symptoms of hypothyroidism include unexplainable weight gain, fatigue, and depression. Some people attribute their weight gain to hypothyroidism but in reality, this disease cannot cause you to gain more than 10 to 20 pounds, most of which is fluid. I
If you're feeling tired for no reason or have any of the other symptoms of hypothyroidism, such as dry skin, a pale, puffy face, constipation or a hoarse voice, see your doctor at once. You may also need to visit your doctor for periodic testing of your thyroid function if you've had previous thyroid surgery, treatment with radioactive iodine or anti-thyroid medications, or radiation therapy to your head, neck or upper chest.
If you have high blood cholesterol, talk to your doctor about whether hypothyroidism may be a cause. And if you're receiving hormone therapy for hypothyroidism, schedule follow-up visits as often as your doctor recommends. Initially, it's important to make sure you're receiving the correct dose of medicine. And over time, the dose you need to keep your thyroid functioning normally may change (Mayo clinic). Some good sites that offer more detailed explanations and information about this disease can be found in the following:
The Mayo Clinic www.mayoclinic.com Medicine Net www.medicinet.com New York Thyroid Center http://cpmcnet.columbia.edu/dept/thyroid/index.html Annex A. Thyroid Gland IIlustration. (Source, Mayoclinic.com, 2004)
Bibliographies
Professional Sources
Brown, V. (2003). Disrupting a delicate balance: environmental effects on the thyroid, 2003 Environmental Health Perspectives, Volume: 111. Issue: 12, p. 642+.
Dobson, J. E. (1998). The Iodine Factor in Health and Evolution. Geographical Review 88 (1): 1-28.
Foster, H. D., (2002). Commentary: Neandertals and the Thyroid Gland; the Selenium Connection. The Geographical Review. Volume: 92. Issue: 1. p. 89+.
Matovinovic, G. J.. Endemic Goitre and Cretinism at the Dawn of the Third Millennium, 1983. Annual Review of Nutrition 3: 341-412.
Renner, R. New thyroid theory: how maternal hormone affects developing brains, 2003. Environmental Health Perspectives. Volume: 111. Issue: 1. P. 25+.
Non-professional Sources
Briscoe, J., M.D., Mercury 2: What Are Results of Thyroid Trouble, July 17, 2005. MERCURY MEDIC. The Sunday Mercury, P. 32.
Kilgore, C. Retrospective study shows hypothyroidism tied to lower breast Cancer risk, 2005. OB/GYN News.
Zamula, E., Many Treatments Available: Thyroid Disorders Often Unsuspected, December 1992. FDA Consumer. Volume: 26. Issue: 10. P. 34.
Electronic Sources
Lam, M. M.D., Hypothyroidism, 2004. Dr.Lam.com Accessed 27 Nov. 2005 http://www.drlam.com/physician_support/hypothyroidism.cfm Hypothyroidism. Mayo Clinic.com, 2005. Accessed 27 Nov. 2005 http://www.mayoclinic.com/health/hypothyroidism/DS00353
Hypothyroidism. MedicineNet.com, 2005. Accessed 27 Nov. 2005 http://www.medicinenet.com/hypothyroidism/page4.htm
Hypothyroidism, New York thyroid center, 2005. Accessed 27 Nov. 2005
http://cpmcnet.columbia.edu/dept/thyroid/HypothyroidismHP.html
HYPOTHYROIDISM
NAME
SCHOOL
TABLE OF CONTENTS
INTRODUCTION 3
ANATOMY AND PATHOPHYSIOLOGY 3
SIGNS AND SYMPTOMS 7
RISK FACTORS 8
DIAGNOSTIC MEASURES 9
TREATMENT 10
RECENT DEVELOPMENTS 11
COMPLICATIONS 12
BIBLIOGRAPHIES 17 Introduction
This document aims to provide you with a comprehensive overview of a thyroid disease called Hypothyroidism. Section one will discuss the anatomy and pathophysiology of the disease to show its common causes and what specific parts of the body are affected. The next section will detail how hypothyroidism is detected and the possible complications that may arise if it is left untreated. Treatment procedures will be highlighted in succeeding section including preparations, …show more content…
possible complications or side effects and medications that are usually given to patients with this type of disease. After which, literature on some of the most recent developments involving treatment, devices, research into causative factors and the like will be presented. The psychosocial aspects of the disease will also be discussed briefly and some recommendations on where else to locate new information about the disease process will be indicated. It should be noted that this document is by no means a prescriptive form of information. It does not intend to replace professional opinion nor serve as a substitute. If you experience any of the symptoms of hypothyroidism, it is still best to seek help from your doctor or health center.
Anatomy and Pathophysiology
As mentioned, Hypothyroidism is a disease of the thyroid, a gland which regulates the body's metabolism, heart rate, blood pressure, and body temperature, among other functions. It is a butterfly-shaped gland located at the base of your neck, just below your Adam's apple (please see Annex A for an image of the thyroid gland). Although it weighs less than an ounce, the thyroid gland has an enormous effect on your health (Mayo clinic, 2004). In fact, a variety of disorders can plague it, including autoimmune disorders, benign and malignant tumors, and goiter (an enlargement of the thyroid that may be caused by either over- or under-production of thyroid hormone) (Brown, V. Disrupting a delicate balance: environmental effects on the thyroid, 2003).
In order to produce your thyroid's two principal products--thyroxine (T4) and triiodothyronine (T-3), together known as the "thyroid hormone", the body utilizes an element called Iodine. This hormone maintains the rate at which your body uses fats and carbohydrates, burn calories, help regulate your body temperature, influence your heart rate and help in controlling the production of protein. Your thyroid gland also produces calcitonin, a hormone that regulates the amount of calcium in your blood.
The rate at which thyroxine and triiodothyronine are released is controlled by your pituitary gland and your hypothalamus an area at the base of your brain that acts as a thermostat for your whole system. First, the hypothalamus signals the pituitary gland to produce a hormone called thyroid-stimulating hormone (TSH). TSH signals the thyroid gland itself to capture iodine from the blood to synthesize, store, and release T-4. Once T-4 has reached an adequate circulating level, the hypothalamus and pituitary reduce their output of Thyroid Releasing Hormone (TRH) and TSH until the T-4 level again drops. [T.sub.4] circulates in the blood both freely and bound to carrier proteins. When T-4 finally reaches the cells, it is converted to T-3 which is actually the biologically active form. T-3 can alsoe released by the thyroid and can stick to carrier proteins.
Sometimes, the thyroid fails to produce enough hormones. The Mayo Clinic (2004) provides a comprehensive list of possible causes for this condition:
Autoimmune disease (Hashimoto's thyroiditis). Autoimmune disorders occur when your immune system produces antibodies that attack your own tissues. Sometimes this process occurs within the thyroid gland. Scientists aren't sure why the body produces antibodies against itself. Some think a virus or bacteria might trigger the response, while others believe a genetic flaw may be involved. Most likely, autoimmune diseases result from more than one factor. But however it happens, these antibodies affect the thyroid's ability to produce hormones.
Treatment with radioactive iodine. The most common treatment for people who produce too much thyroid hormone (hyperthyroidism) is radioactive iodine. The radioactive material becomes concentrated in the thyroid gland, reducing its function. Often, however, function is reduced too much, resulting in hypothyroidism. Anti-thyroid drugs such as methimazole (Tapazole) also used to treat conditions in which the thyroid produces too much thyroid hormone may cause hypothyroidism as well.
Radiation therapy. Radiation used to treat cancers of the head and neck can affect your thyroid gland and may lead to hypothyroidism.
Thyroid surgery. Removing all or a large portion of your thyroid can diminish or halt hormone production. In that case, you'll need to take thyroid hormones for life.
Medications. A number of medications can contribute to hypothyroidism. One of the most common is lithium, which is used to treat certain psychiatric disorders. If you're taking medication, ask your doctor about its effect on your thyroid gland.
Less often, hypothyroidism may result from one of the following:
Congenital disease. Approximately one in 3,000 babies in the United States is born with a defective thyroid gland or no thyroid gland at all. In most cases, the thyroid gland didn't develop normally for unknown reasons, but some children have an inherited form of the disorder. Often, infants with congenital hypothyroidism appear normal at birth. That's one reason why doctors now recommend that all newborns receive thyroid tests when they're between 24 and 72 hours old.
Pituitary disorder. About 1 percent of cases of hypothyroidism are caused by the failure of the pituitary gland to produce enough TSH usually due to a benign tumor of the pituitary gland.
Pregnancy. Some women develop hypothyroidism during or after pregnancy (postpartum hypothyroidism), often because they produce antibodies to their own thyroid gland. Left untreated, hypothyroidism increases the risk of miscarriage, premature delivery and preeclampsia a condition that causes a significant rise in a woman's blood pressure during the last three months of pregnancy. It can also seriously affect the developing fetus.
Iodine deficiency.
The trace mineral iodine found primarily in seafood, seaweed, plants grown in iodine-rich soil and iodized salt is essential for the production of thyroid hormones. Before the 1920s, it wasn't unusual for people to develop hypothyroidism because they consumed too little of this mineral. But the addition of iodine to table salt has virtually eliminated this problem in the United States. In other parts of the world, however, as many as 200 million people may have iodine deficiencies.
The World Health Organization (WHO) estimates that 740 million people worldwide suffer from iodine deficiency--the most common cause of preventable thyroid disease and mental retardation in the world--and only about 57% of people in the developing world consume iodized salt, the primary means of correcting iodine deficiency. Iodine deficiency is common in inland areas of the world where people do not have access to iodine-rich foods such as ocean fish, kelp, and sea salt, or where they consume foods that interfere with the body's uptake of iodine (Brown, …show more content…
2003).
Diet can also interfere in various ways with the optimum operation of the thyroid gland (Dobson, The Iodine Factor in Health and Evolution, 1998). Apart from a failure to consume foods containing iodides, iodine deficiency diseases and disorders such as hypothyroidism can occur from the excessive intake of goitrogens, substances that prevent the use of iodine by the thyroid. These include maize, sweet potato, cabbage, cassava, kale, groundnuts, soybeans, turnips, and the seeds of cabbage, mustard, and rape (Matovinovic, G. J. Endemic Goitre and Cretinism at the Dawn of the Third Millennium. 1983). Apart from these dietary goitrogens, hard water has also been found to cause endemic goiter, both in humans and in animals used in experiments. Although hard water may contain more iodine than does soft water, goiter is widespread in hard-water regions (Foster, H. Commentary: Neandertals and the Thyroid Gland; the Selenium Connection, 2002).
Signs and Symptoms
The symptoms of hypothyroidism are mainly dependent on the amount of decrease in thyroid hormone and duration of time that the decrease has been present. For most patients, the symptoms are mild and can often be confused with other problems. At first, you may barely notice symptoms such as fatigue and sluggishness, or you may simply attribute them to getting older. But as your metabolism continues to slow, you may develop more obvious signs and symptoms, including the following (New York Thyroid Center, Hypothyroidism, 2005):
· fatigue and muscle swelling or cramps (mainly in the arms and legs)
· tingling in the fingers
· loss of equilibrium
· weight gain
· dry skin and cold intolerance
· yellow skin
· coarseness or loss of hair
· goiter (enlarged thyroid causing a lump in the neck)
· constipation
· hoarseness
· memory and mental impairment
· decreased concentration
· depression
· irregular or heavy menstruation
· infertility or miscarriages
· slowed heart rate
· myxedema: fluid infiltration of the tissues causing puffiness (mainly in the face)
Risk Factors
Although anyone can develop hypothyroidism, it occurs mainly in women older than 40, and the risk of developing the disorder increases with age. You also have an increased risk if you:
· Have a close relative, such as a parent or grandparent, with an autoimmune disease
· Have diabetes, which moderately increases the risk that you'll develop hypothyroidism during or after pregnancy
· Have been treated with radioactive iodine or anti-thyroid medications
· Received radiation to your neck or upper chest, even if the treatment occurred years ago
· Have had thyroid surgery (thyroidectomy) (Mayo Clinic, 2004)
Recent studies show that a mother's thyroid hormone has direct impacts on her baby's brain development. Congenital hypothyroidism may result from lack of thyroid hormone late in pregnancy and the first months of a child's life. If untreated, this condition results in moderate to severe mental retardation, growth failure, deafness, and neurological problems. Those symptoms can be ameliorated by administering synthetic thyroid hormone before the child is three months old. After that, it's too late--the defects are permanent (Renner, R. New thyroid theory: how maternal hormone affects developing brains, 2003).
Diagnostic Measures
When hypothyroidism is suspected, your doctor bases the diagnosis on your symptoms and blood tests that measure the amount of thyroxine and TSH circulating in the blood. A low level of thyroxine are indications that the thyroid is underactive (Zamula, E. Many Treatments Available: Thyroid Disorders Often Unsuspected, 1992).
In the past, doctors weren't able to detect hypothyroidism until symptoms were fairly advanced. Now, they use the sensitive TSH test, which enable them to diagnose thyroid disorders much earlier even before you experience the symptoms. Since the TSH test is the best screening test, your doctor will likely check TSH first and follow with a thyroid hormone test if needed. TSH tests also play an important role in managing hypothyroidism by helping your determine the right dosage of medication, both at the onset and in the long run. In addition, TSH tests are used to help diagnose a condition called subclinical hypothyroidism, which usually manifests no outward signs or symptoms. In this condition, you have normal blood levels of T-3 and T-4, but higher than normal levels of TSH.
Treatment
Hypothyroidism is usually treated with the synthetic drug thyroxine.
Since it mimics the action of natural thyroid hormone, it has very few side-effects. However, if the dose is too high, symptoms of hyperthyroidism can occur such as intolerance of hot temperature, excessive sweating, weight loss, anxiety and insomnia to name a few. Other side-effects are muscle weakness, abnormal heart beats and chest pain. If you do experience side-effects it is certainly worth discussing them with your doctor (Briscoe, J., M.D., Mercury 2: What Are Results of Thyroid Trouble, 2005) MERCURY MEDIC..
Some doctors may prefer Amour Thyroid that contains natural thyroid hormones. Natural hormones also have T1 and T2 in addition to T3 and T4. Armour thyroid is a natural desiccated thyroid. It was the only available treatment for hypothyroidism for some 50 years. Because of concern about their variable potency, these extracts have been considered obsolete for some time by all but a few natural prescribers (Lam, M. M.D., Hypothyroidism,
2004).
While synthetic thyroid hormone made in the laboratory by drug companies usually contain T3 (Cytomel) and T4 (levothyroxine) or combinations (Thyrolar) of these two. Patients with hypothyroidism show greater improvements in mood and brain function if they receive treatment Armour thyroid rather than Synthroid (thyroxin). Some studies found that a majority of patients, however, might feel better on a combination of hormones such as combination of T3 and T4 instead of single T4 alone (Lam, 2004).
Therapy for hypothyroidism should be monitored at approximately 6 week intervals until stable. During visits, a blood sample is checked for TSH to determine if the appropriate amount of thyroid replacement is being given. The goal is to maintain the TSH within normal limits. Depending on the lab used, the absolute values may vary, but in general, a normal TSH range is between 0.5 to 5.0uIU/ml. Once stable, the TSH can be checked yearly. Over-treating hypothyroidism with excessive thyroid medication is potentially harmful and can cause problems with heart palpitations and blood pressure control and can also contribute to osteoporosis. Every effort should be made to keep the TSH within the normal range (Medicine.net, 2005).
Levothyroxine causes virtually no side effects when used in the appropriate dose and is relatively inexpensive. If you change brands, let your doctor know to ensure you're still receiving the right dosage. Also, don't skip doses or stop taking the drug because you're feeling better. If you do, the symptoms of hypothyroidism will gradually return. People with hypothyroidism need to take medication for the rest of their lives.
Certain medications, supplements and even some foods may affect your ability to absorb levothyroxine. Talk to your doctor if you eat large amounts of soy products or a high-fiber diet or you take any of the following (Mayo Clinic):
Iron supplements
Cholestyramine (Questran)
Aluminum hydroxide, which is found in some antacids
Sodium polystyrene sulfonate (Kayexalate)
Sucralfate
Recent Developments
A recent interesting finding showed that women treated for hypothyroidism had less tendency to develop primary breast cancer and more likely to have more indolent disease when they did develop breast cancer than women with normal thyroid function. In this study, women with primary hypothyroidism were found to have had a 61% lower risk of developing invasive breast cancer, and women with breast cancer were 57% less likely to have hypothyroidism, compared with healthy women. This finding strengthens the possibility of thyroid hormones as having a significant role in the treatment of breast cancer (Kilgore, C. Retrospective study shows hypothyroidism tied to lower breast Cancer risk, 2005).
Complications
When hypothyroidism isn't treated, symptoms can gradually become more severe. Constant stimulation of your thyroid to release more hormones may lead to an enlarged thyroid (goiter). In addition, you may become more forgetful, your thought processes may slow or you may feel depressed (Mayo Clinic, 2004).
Another complication of severe and long-standing hypothyroidism is called myxedema. If you have this disorder, you may become very cold and drowsy, and may eventually lapse into a coma. Uncommon in tropical climates, this rare condition may be brought on by cold weather, infection, or the use of some drags, especially sedatives. About 50 to 60 percent of people with hypothyrnid coma die. FDA approved Triostat (liothyronine sodium), an intravenous thyroid hormone replacement drug for the treatment of myxedema coma and pre-coma, in 1991 (Zamula, 1992).
Other complications are:
Heart problems. Hypothyroidism may also be associated with an increased risk of heart disease, primarily because high levels of low-density lipoprotein (LDL) cholesterol the "bad" cholesterol can occur in people with an underactive thyroid. Even subclinical hypothyroidism, a more benign condition than true hypothyroidism can cause an increase in total cholesterol levels and impair the pumping ability of your heart. Hypothyroidism can also lead to an enlarged heart.
Mental health issues. Depression may occur early in hypothyroidism and may become more severe over time. Hypothyroidism can also cause decreased sexual desire (libido) in both men and women and can lead to slowed mental functioning.
Myxedema. This rare, life-threatening condition is the result of long-term, undiagnosed hypothyroidism. Its symptoms include intense cold intolerance and drowsiness followed by profound lethargy and unconsciousness. A myxedema coma may be triggered by sedatives, infection or other stress on your body. If you have symptoms of myxedema, you need immediate emergency medical treatment.
Birth defects. Babies born to women with untreated thyroid disease may have a higher risk of birth defects than do babies born to healthy mothers. Doctors have long known that these children are more prone to intellectual and developmental problems, but recent studies also show a link between hypothyroid pregnancies and birth defects such as cleft palate. A connection also exists between hypothyroid pregnancies and heart, brain and kidney problems.
Infants with untreated congenital hypothyroidism are also at risk of serious problems with both physical and mental development. But if the condition is diagnosed within the first few months of life, the chances of normal development are excellent (Mayo Clinic, 2004).
Psychosocial Aspect
Hypothyroidism may affect your social behavior when you begin to feel the more evident symptoms, especially those that have to do with mood changes. As mentioned, among the symptoms of hypothyroidism include unexplainable weight gain, fatigue, and depression. Some people attribute their weight gain to hypothyroidism but in reality, this disease cannot cause you to gain more than 10 to 20 pounds, most of which is fluid. I
If you're feeling tired for no reason or have any of the other symptoms of hypothyroidism, such as dry skin, a pale, puffy face, constipation or a hoarse voice, see your doctor at once. You may also need to visit your doctor for periodic testing of your thyroid function if you've had previous thyroid surgery, treatment with radioactive iodine or anti-thyroid medications, or radiation therapy to your head, neck or upper chest.
If you have high blood cholesterol, talk to your doctor about whether hypothyroidism may be a cause. And if you're receiving hormone therapy for hypothyroidism, schedule follow-up visits as often as your doctor recommends. Initially, it's important to make sure you're receiving the correct dose of medicine. And over time, the dose you need to keep your thyroid functioning normally may change (Mayo clinic). Some good sites that offer more detailed explanations and information about this disease can be found in the following:
The Mayo Clinic www.mayoclinic.com Medicine Net www.medicinet.com New York Thyroid Center http://cpmcnet.columbia.edu/dept/thyroid/index.html Annex A. Thyroid Gland IIlustration. (Source, Mayoclinic.com, 2004)
Bibliographies
Professional Sources
Brown, V. (2003). Disrupting a delicate balance: environmental effects on the thyroid, 2003 Environmental Health Perspectives, Volume: 111. Issue: 12, p. 642+.
Dobson, J. E. (1998). The Iodine Factor in Health and Evolution. Geographical Review 88 (1): 1-28.
Foster, H. D., (2002). Commentary: Neandertals and the Thyroid Gland; the Selenium Connection. The Geographical Review. Volume: 92. Issue: 1. p. 89+.
Matovinovic, G. J.. Endemic Goitre and Cretinism at the Dawn of the Third Millennium, 1983. Annual Review of Nutrition 3: 341-412.
Renner, R. New thyroid theory: how maternal hormone affects developing brains, 2003. Environmental Health Perspectives. Volume: 111. Issue: 1. P. 25+.
Non-professional Sources
Briscoe, J., M.D., Mercury 2: What Are Results of Thyroid Trouble, July 17, 2005. MERCURY MEDIC. The Sunday Mercury, P. 32.
Kilgore, C. Retrospective study shows hypothyroidism tied to lower breast Cancer risk, 2005. OB/GYN News.
Zamula, E., Many Treatments Available: Thyroid Disorders Often Unsuspected, December 1992. FDA Consumer. Volume: 26. Issue: 10. P. 34.
Electronic Sources
Lam, M. M.D., Hypothyroidism, 2004. Dr.Lam.com Accessed 27 Nov. 2005 http://www.drlam.com/physician_support/hypothyroidism.cfm Hypothyroidism. Mayo Clinic.com, 2005. Accessed 27 Nov. 2005 http://www.mayoclinic.com/health/hypothyroidism/DS00353
Hypothyroidism. MedicineNet.com, 2005. Accessed 27 Nov. 2005 http://www.medicinenet.com/hypothyroidism/page4.htm
Hypothyroidism, New York thyroid center, 2005. Accessed 27 Nov. 2005
http://cpmcnet.columbia.edu/dept/thyroid/HypothyroidismHP.html