Hypothyroidism : Complications

Myxedema coma, the most severe form of hypothyroidism, is rare. It may be caused by an infection, illness, exposure to cold, or certain medications in people with untreated hypothyroidism. Symptoms and signs of myxedema coma include: Below normal ...

Thyroid hormone replacement therapy generally maintains normal thyroid hormone levels unless treatment is interrupted or discontinued.

Thyroid hormone replacement therapy generally maintains normal thyroid hormone levels unless treatment is interrupted or discontinued. KEY TERMS Cretinism -Severe hypothyroidism that is present at birth and characterized by severe mental retardati...

A goiter is an enlargement of the thyroid gland. It is not cancer.

Goiter is a swelling in the neck, caused by a malfunction of the thyroid gland. The thyroid gland, located in the base of the neck, absorbs iodine from the blood and uses this to produce hormones that regulate many body functions, including EXAMPLES OF IODINE-RICH FOODS Food Serving size Micrograms of iodine Source: FDA's Total Diet Study (1982-1984). Cod or haddock, cooked 3-½ oz (100 g) 175 Chocolate milkshake (fast food) 1 average 158 Homemade meatloaf 3-½ oz (100 g) 123 Lima beans, boiled ½ cup (90 g) 104 Chocolate ice cream 1 cup (133 g) 94 Corn grits, cooked ½ cup (120 g) 86 Chocolate milk, low-fat 1 cup (250 g) 83 Yogurt, low-fat 1 cup (227 g) 73 Milk, low-fat 1 cup (244 g) 66 Milk, skim 1 cup (246 g) 64 Milk, whole 1 cup (244 g) 61 growth, nerve function, and absorption of vitamins and calcium. If the thyroid gland does not receive enough iodine from the blood, the gland may enlarge, causing a goiter. A goiter can also develop if the thyroid gland does not produce enough thyroid hormones, a condition called hypothyroidism. Goiter is also present in hyperthyroidism, when the gland produces too much thyroid hormone. A common cause of goiter around the world is lack of iodine in the diet. The thyroid needs iodine to produce thyroid hormones, and if sufficient iodine is not available, the gland enlarges because it is working harder. The main dietary sources of iodine are grains and vegetables grown in iodine-rich soil, and saltwater fish and seafoods. The Recommended Daily Allowance (RDA) for iodine for adolescents and adults is 150 micrograms per day. To combat iodine deficiency in the U.S., iodine has been added to salt since 1924. The body needs only very small amounts of iodine for healthy thyroid function, so iodized salt usually provides an adequate dietary amount. There are two forms of thyroid disorder, however, that affect children regardless of diet. Congenital hypothyroidism is a disorder in which a child may be born with an underactive thyroid gland. Symptoms appear when the baby is six to twelve weeks old, and include cool, mottled or yellowish skin, coarse hair, and a dull appetite. The baby's neck will look unusually short and fat. The facial features are also affected: the bridge of the nose is underdeveloped, so the nose appears flat and the eyes seem widely spaced, and the tongue is thick and protrudes. Hypothyroidism slows the baby's growth and development, and the child may have weak muscles and slow reflexes. If untreated, this condition can lead to mental retardation. Hypothyroidism can also begin later in life, in a child born with normal thyroid function. It usually begins when a child is between 11 and 14 years old. Onset of this disease is not related to diet, but it may be a side effect of an auto-immune disease that attacks the thyroid. Children with this disease may develop dry, coarse hair and skin, poor circulation, and low blood pressure. Goiter may appear, along with the facial characteristics of the hypothyroid baby. The disease slows the child's growth, and puberty is usually delayed. All the symptoms of acquired hypothyroidism can be treated with medical intervention, and the condition does not lead to mental retardation. Diagnosis is made with a simple blood test, and treatment involves replacing the deficient thyroid hormones. The goiter may need to be removed surgically. Hyperthyroidism, or overproduction of thyroid hormones, usually affects older women, and only rarely affects children. In children with this condition, goiter may develop, and the eyes may bulge out. Just the opposite of hypothyroidism, the hyperthyroid child grows faster than normal and may have flushed, warm skin, and increased heart rate. The child may be restless and irritable, unable to concentrate, and tire easily. All these symptoms can be reversed by medical treatment. Treatment usually involves medication that blocks the excess hormone production. Surgery may be needed to remove the thyroi

An example of grade III (large and visible) goiter. Most cases of goiter in the developing world are due to an iodine deficiency. Unable to meet the body's hormonal needs, the thyroid becomes enlarged to compensate. [© Lester V. Bergman/Corbis. Reproduced by permission.] A goiter is a noncancerous enlargement of the thyroid gland in the front of the neck. Many conditions can cause goiter, but the most common is a lack of sufficient iodine in the diet , which is usually a result of the soil in which food is grown being iodine-poor—a condition that occurs in many mountainous regions away from the sea. Iodine is required for the production of thyroid hormones , which regulate the body's metabolism . About 740 million people have goiters, but the percentage varies greatly by region (eastern Mediterranean: 32%; Africa: 20%: Europe: 15%; Southeast Asia: 12%; western Pacific: 8%; the Americas: 5%). Surveying communities for goiters is one of the best ways of detecting iodine deficiency, which, if not treated, can cause stillbirths , miscarriages , cretinism , mental impairments, deafness, and dwarfism. Iodine deficiency is the most common preventable cause of brain damage and mental retardation, affecting about 50 million people worldwide. However, these disorders have been tremendously reduced simply by using table salt fortified with iodine. Adults require at least 20 micrograms of iodine daily, but 150 micrograms is recommended. Seafoods are excellent sources, while the iodine content of other foods varies depending on animal feed and soil. Iodism (iodine poisoning) is a rare condition that results in weakness, swollen salivary glands, a metallic taste in the mouth, and a runny nose. SEE ALSO M INERALS . Donna Staton Marcus Harding

Goiter is an enlargement of the thyroid gland. It may be diffuse, involving all thyroid tissue, or it may be caused by one or more lumps (nodules)—called nodular goiter. Diffuse goiter reflects an underlying thyroid problem, most commonly iodine deficiency in iodine-deficient areas of the world, where nearly 1 billion people may be subject to the disorder. In the United States, iodine deficiency is rare (because of widespread use of iodized salt) and goiter is most commonly caused by Graves' disease or Hashimoto's disease. Nodular goiter affects 3 to 5 percent of adults, mainly women. Nodules may reflect thyroid cancer (in 5% of cases), but the remainder are benign processes due to multiple causes. Cancers can be distinguished from benign disease by microscopic evaluation of thyroid tissue obtained by fine-needle aspiration biopsy. M ARTIN I. S URKS ( SEE ALSO : Hyperthyroidism ; Hypothyroidism ; Iodine ; Thyroid Disorders ; Thyroid Function Tests )

Goiter refers to any visible enlargement of the thyroid gland.

Primary infertility describes couples who have never been able to become pregnant after at least 1 year of unprotected sex (intercourse. Secondary infertility describes couples who have been pregnant at least once, but have not been able to become pregnant again.

Infertility is the failure of a couple to conceive a pregnancy after trying to do so for at least one full year. In primary infertility, pregnancy has never occurred. In secondary infertility, one or both members of the couple have previously conceived, but are unable to conceive again after a full year of trying.

Infertility is the failure to conceive a pregnancy after attempting for at least one full year. In primary infertility, pregnancy has never occurred. In secondary infertility, one or both members of the couple have previously conceived, but are unable to conceive again after a full year of attempting.

Infertility is the failure of a couple to conceive a pregnancy after trying to do so for at least one full year. In primary infertility, pregnancy has never occurred. In secondary infertility, one or both members of the couple have previously conceived, but are unable to conceive again after a full year of trying.

Depression may be described as feeling sad, blue, unhappy, miserable, or down in the dumps. Most of us feel this way at one time or another for short periods. True clinical depression is a mood disorder in which feelings of sadness, loss, anger, or frustration interfere with everyday life for an extended period of time. See also: Adolescent depression; Depression in the elderly.

Depression, also known as depressive disorders or unipolar depression, is a mental illness characterized by a profound and persistent feeling of sadness or despair and/or a loss of interest in things that once were pleasurable. Disturbance in sleep, appetite, and mental processes are a common accompaniment.

Depression is sometimes referred to as the common cold of mental illness. It is a debilitating disease with significant societal costs. It is, however, one of the most clearly defined and treatable of mental illnesses. Technically, the term "depression" is used to cover a variety of symptomatic conditions, all characterized by negative mood and a loss of pleasure. Together these conditions comprise a spectrum ranging from major depression to dysthymia to adjustment reactions to normal grief and sadness. At one extreme of this continuum lies major depressive disorder, a syndrome characterized by severe episodes of depressed mood accompanied by loss of sleep, appetite, concentration, energy, and hope. The depressed mood must persist for greater than two weeks in order to warrant this diagnosis. At the other end of the continuum lies the diagnosis of dysthymia, which is characterized by a lower level of mood disturbance that persists chronically; that is, involving more days than not for a period of two years or greater. Many patients complain of depressed mood but do not fit neatly into either of these two categories. These patients' symptoms are frequently best accounted for as a reaction to an acute life stressor. These reactions are typically nonpathological and resolve with time, but they may constitute an adjustment reaction if normal functioning is sufficiently disturbed. Depression is both common and costly. It has a lifetime prevalence of 5 to 10 percent of women and 2 to 5 percent of men. It is an expensive disorder in both direct and indirect terms, as depression causes a higher degree of functional disability than many medical illnesses including diabetes, chronic lung disease, and arthritis. Additional costs to society result from the effect of untreated depression on the treatment of medical illnesses, where it contributes to longer hospital stays and morbidity. This has been particularly well demonstrated in the treatment of myocardial infarction (heart attack), where the presence of major depression has consistently been found to increase mortality. Depressive illness is thought to result from a combination of biological and psychological factors. The biological component is strongly suggested by the high genetic concordance of depressive disorders. In the twenty-first century, there are various competing theories about the nature of this genetic/biological contribution, but the available data do not yet indicate the specific nature of the illness. The psychological component is similarly suggested by the correlation of onset of major depression with negative life events and with the increased risk of depression in individuals who experienced abuse in childhood. A variety of psychological theories exist and are linked to models of psychotherapeutic treatment. Interpersonal psychotherapists, for example, emphasize the role of grieving due to the loss of an important relationship or a transition in social roles (e.g., transition from working to retirement, marriage to divorce). Cognitive therapists emphasize a mind-set of construing life events in a way that leads to depression. Alternately, psychodynamic therapists search for the ways that unconscious coping processes and repetitive relational patterns result in negative effects. A commonly postulated mechanism would include the turning of anger in on the self. For example, a depressed woman may feel critical of herself rather than direct her anger toward an abusive spouse. Treatment of depression parallels theories of etiology in that both biological and psychological treatments exist and have been efficacious. A number of different antidepressant medications have been developed, including monoamine oxidase (MAO) inhibitors, tricyclic antidepressants, and selective serotonin reuptake inhibitors (SSRI). These medicines have demonstrated efficacy in both the treatment of acute depressive episodes and in the prevention of relapses. A variety of psychological therapie

Heart disease is any disorder that affects the heart's ability to function normally. Various forms of heart disease include: Alcoholic cardiomyopathy; Aortic regurgitation; Aortic stenosis; Arrhythmias; Cardiogenic shock; Congenital heart disease; Coronary artery disease (CAD; Dilated cardiomyopathy; Endocarditis; Heart attack (myocardial infarction; Heart failure; Heart tumor; Hypertrophic cardiomyopathy; Idiopathic cardiomyopathy; Ischemic cardiomyopathy; Acute mitral regurgitation; Chronic mitral regurgitation; Mitral stenosis; Mitral valve prolapse; Peripartum cardiomyopathy; Pulmonary stenosis; Stable angina; Unstable angina; Tricuspid regurgitation.

The heart, which is about the size of a human fist, is the body's largest, strongest, and most important muscle. The heart continuously pumps blood through the body, helps regulate and prolong health, and controls the flow (circulation) of blood to the lungs, organs, muscles, and tissues in the body. Heart disease is a leading cause of debilitation and death worldwide in men and women over age sixty-five. In many countries heart disease is viewed as a "second epidemic," replacing infectious diseases as the leading cause of death. It is especially devastating in countries that do not have adequate health care. There are many types of diseases and disorders that affect the heart.

Heart disease is the narrowing or blockage of the arteries and vessels that provide oxygen and nutrient-rich This illustration shows hypertrophic muscle in the heart. The lesions are due to an incompetent aortic valve. ( Illustration by Bryson Biomedical Illustrations, Custom Medical Stock Photo . Reproduced by permission. ) blood to the heart. It is caused by atherosclerosis , an accumulation of fatty materials on the inner linings of arteries that restricts blood flow. When the blood flow to the heart is completely cut off, the result is a heart attack because the heart is starved of oxygen.

Hypothyroidism is a condition in which the thyroid gland does not make enough thyroid hormone. See also: Chronic thryoiditis (Hashimoto's disease; Subacute thyroiditis; Silent thyroiditis; Neonatal hypothyroidism.

Hypothyroidism, or a condition of insufficient thyroid hormone in the body, develops when the thyroid gland fails to produce or secrete as much thyroxine (T 4 ) and triiodothyronine (T 3 ) as the body needs. Because T 4 regulates such essential functions as heart rate, digestion, physical growth, and mental development, an insufficiency of this hormone can slow life-sustaining processes, damage organs and tissues in every part of the body, and lead to life-threatening complications.

Hypothyroidism, or underactive thyroid, develops when the thyroid gland fails to produce or secrete as much thyroxine (T 4 ) and triiodothyonine (T 3 ) as the body needs. Because these thyroid hormones regulate such essential functions as heart rate, digestion, physical growth, and mental development, an insufficient supply of this hormone can slow metabolic processes, damage organs and tissues in every part of the body, and lead to life-threatening complications.

Hypothyroidism, or underactive thyroid, develops when the thyroid gland fails to produce or secrete as much thyroxine (T 4 ) as the body needs. Because T 4 regulates such essential functions as heart rate, digestion, physical growth, and mental development, an insufficient supply of this hormone can slow life-sustaining processes, damage organs and tissues in every part of the body, and lead to life-threatening complications.

Birth defects are physical abnormalities that are present at birth; they are also called congenital abnormalities. More than 3,000 have been identified.

Question: Does folic acid use help prevent birth defects? Answer: There is good evidence that you can reduce the risk of certain birth defects (spina bifida and anencephaly) by taking a daily dose of 400 micrograms folic acid from 1 month before conception through the first trimester of pregnancy. Therefore, if you would like to become pregnant in the near future, you should take a multivitamin with this amount of folic acid. Women who have had a baby with a neural tube defect will need a higher dose of folic acid. If you have had a baby with a neural tube defect, you should take 400 micrograms of folic acid every day, even when you are not planning to become pregnant. If you plan to become pregnant, you should talk to your doctor and increase your folic acid intake to 4 milligrams each day during the month before you become pregnant until at least the 12th week of pregnancy.

Any unusual variation or abnormality in the shape, structure, and/or function of an organ, body part, or tissue is commonly referred to as a birth defect. However, congenital anomaly is the more accurate and preferred term, since birth defect can be misinterpreted to mean a defect produced by the birthing process. Congenital anomalies may be external or internal, single (isolated) or multiple, major or minor, and by definition are present at (and almost always before) birth, although in some cases detection/diagnosis occurs well after birth. As a group, congenital anomalies are common, have a wide range of clinical severity, and can develop, in one form or another, in any anatomical structure or location. There are many different causes of congenital anomalies, known and unknown, but in terms of how they develop, there are four major types: malformations, deformations, disruptions, and dysplasias.

Defects present at birth, resulting from hereditary factors, environmental influences, or maternal illness. Birth or congenital defects are present at birth and result from hereditary factors, environmental influences, or maternal illness. Such defects range from very minor, such as a dark spot or birthmark that may appear anywhere on the infant's body, to more serious conditions that may result in marked disfigurement or limit the lifespan of the child. A number of factors individually or in combination may cause birth defects. Heredity plays a major role in passing birth defects from one generation to the next. Such conditions as sickle-cell anemia, color blindness, deafness, and extra digits on the hands or feet are hereditary. The condition may not appear in every generation, but the defective gene is usually passed on. Low birth weight is the most common birth defect, with one in every 15 babies being born at less than their ideal weight. Weights between 5 lb, 8 oz (2,500 g) and 3 lb, 5 oz (1,500 g) are considered low. Low birth weight may occur if the baby is born prematurely, before the normal gestation period of 38 weeks has elapsed, or after a normal gestation period. Premature birth, other than being a birth defect in itself, may also have accompanying effects. A baby born before the 28th week of gestation, for example, may have great difficulty breathing because the lungs have not developed fully. Prenatal conditions can cause birth defects. For example, the mother's exposure to chemicals such as mercury or to radiation during the first three months of pregnancy may result in an abnormal alteration in the growth or development of the fetus. The mother's diet may also be a factor. A balanced, healthy diet is essential to the proper formation of the fetus because the developing baby receives all of its nutrition from the mother. Prenatal development of the fetus may also be affected by disease that the mother contracts, especially any that occur during the first trimester (three months) of pregnancy. For example, if a pregnant woman contracts German measles, or rubella, the virus may cross the placenta and infect the fetus. The rubella virus interferes with the fetus's normal metabolism and cell movement and can cause blindness (from cataracts), deafness, heart malformations, and mental retardation. The risk of fetal damage resulting from maternal rubella infection is greatest during the first month of pregnancy (50%) and declines with each succeeding month. It is especially important that the mother not smoke, consume alcohol, or take drugs while she is pregnant. Drinking alcohol heavily can result in fetal alcohol syndrome (FAS). Newborns with FAS have small eyes and a short, upturned nose that is broad across the bridge, making the eyes appear farther apart than normal. These babies are also underweight at birth and do not catch up as time passes. They often have some degree of mental retardation and may exhibit behavior problems. A mother who continues to use illicit drugs, such as heroin, crack, or cocaine, will have a baby who is addicted to its mother's drug. The addiction may not be fatal, but the newborn will be physically uncomfortable and disagreeable until the addiction is controlled. Some therapeutic drugs taken by pregnant women have also been shown to produce birth defects. The most notorious example is thalidomide, a mild sedative. During the 1950s women in more than 20 countries who had taken this drug gave birth to more than 7,000 severely deformed babies. These children suffered from a condition called phocomelia, which is characterized by extremely short limbs, often with no fingers or toes. In 1992, the U.S. Public Health Service published the recommendation that all women of childbearing age consume 0.4 milligrams of folie acid daily to decrease the risk of two common and serious birth defects, spina bifida and anencephaly. The Centers for Disease Control estimates that 50-70% of these birth defe

A congenital anomaly may be viewed as a physical, metabolic, or anatomic deviation from the normal pattern of development that is apparent at birth or detected during the first year of life. Under this definition, Mendelian genetic disorders (e.g., phenylketonuria), chromosomal abnormalities (e.g., Down syndrome), tumors (e.g., Wilms' tumor), infections (e.g., rubella, toxoplasmosis, herpes virus, cytomegalovirus, HIV, and syphilis), exposure to teratogenic agents (e.g., cocaine, tobacco, or alcohol), maternal disease (e.g., maternally transmitted autoantibodies, phenylketonuria), and pure bad luck or accident (e.g., a twisted umbilical cord) can all contribute to the development of a congenital anomaly. It is important to determine which of these predisposing conditions have led to the anomaly, because knowledge of the etiologic agent or agents influence not only therapy, but also prevention in the case of future pregnancies. In the United States in 1998, of nearly 4 million live births, just over 45,000 babies (1.15 percent of births) had congenital anomalies of significant enough severity to be recorded on their birth certificates. Musculoskeletal anomalies (e.g., cleft lip/palate, polydactyly, clubfoot) were most common (465 per 100,000 live births), followed by cardiovascular and respiratory malformations (250 per 100,000 live births), urogenital malformations (e.g., malformed genitalia, renal agenesis; 193 per 100,000 live births), central nervous system malformations (e.g., anencephaly, spina bifida, hydrocephalus, microcephalus; 83 per 100,000 live births), gastrointestinal malformations (e.g., rectal atresia/stenosis, tracheo-esophageal fistula, omphalocoele; 83 per 100,000 live births), and multiple malformations attributable to chromosomal anomalies (77 per 100,000 live births). Prevention is the best approach to congenital anomalies. A teratogen can be defined as an agent or factor (e.g., infectious agents, physical agents such as radiation and heat, drug and chemical agents, and maternal metabolic and genetic factors) that can produce abnormalities of form and function in an exposed fetus. As a general rule, organ systems are created during the first trimester of life, structured during the second trimester, and undergo maturation in the third trimester. Thus, teratogens tend to exercise their most destructive effect during the first and second trimesters, underscoring the importance of avoiding exposures to known teratogens from the point a decision is made to consider pregnancy. Prophylaxis can also be practiced, for example, by fortifying the diet with folic acid to reduce the risk of neural tube defects. Abnormal development of major organ systems is readily apparent before the end of the second trimester, making examination of the fetus by ultrasound the simplest form of screening. Some conditions such as obstruction of the urinary tract, are treatable in utero . Evaluation for specific disorders is also available for mothers at risk as a result of genetic background, ethnicity, age, history of exposure, or other routine screening tests. The potential benefits from a given procedure must be balanced against the expected risk. For example, the vast majority of babies with Down syndrome are born to mothers between the age of twenty and thirty; however, the risk of having a baby with Down syndrome begins to increase exponentially after age thirty. Definitive diagnostic procedures, such as chorionic villous sampling and amniocentesis, carry the risk of abortion, hence most physicians discourage these procedures for younger women, where the risk of complications is greater than the prevalence of the suspected anomaly, if the parents have already decided that an induced abortion is out of the question. Gross abnormalities are obvious at birth, whereas many metabolic abnormalities are not immediately apparent and represent a significant, and possibly preventable, hazard to the health and well-being of the patient. I