Submitted in Partial Fulfillment for
Anatomy and Physiology, Ms. Walter
Spring 2013

Things That Can Go Wrong With the Human Body: Hypothyroidism
Introduction:
Over time, a significant amount of problems with the human body have evolved. These problems have been developed due to both environmental and genetic factors. Dietary changes and urbanization have also played a crucial role in the development of problems that may occur. Our bodies contain a number of functioning systems that are all imperative to our survival. Without these systems, our bodies would not function and in turn, we would cease to exist. The endocrine system serves as one of the body’s ways of sending messages to the brain. It includes a number of vital glands that keep our body’s performance stable and functional. The thyroid gland is one of the most important components in the endocrine system. It is located in the neck, just under the voice box. Its primary function is to release the hormones thyroxin (T4) and triiodothyronine (T3) which control body metabolism, by taking iodine from our food and converting it into these hormones. When the levels of T4 and T3 become too low, the pituitary gland must produce a Thyroid Stimulating Hormone (TSH) which then activates the thyroid gland to generate more hormones. (Norman, 2012). If the thyroid gland does not work properly, these hormones cannot be produced on their own. This condition is known as Hypothyroidism. This paper examines the types and causes of hypothyroidism, as well as the symptoms that may occur. Possible treatments and statistics of this health condition are also mentioned and discussed.
Literature Review: Hyperthyroidism most often occurs in women and in those over the age of 50. However it can also occur in infants and young children. It is estimated that as many as 10% of women have some degree of thyroid hormone deficiency (Norman, 2012). Approximately 95% of Hypothyroidism cases arise from problems beginning in the thyroid gland. In these cases, the condition is referred to as Primary Hypothyroidism. Two of the most common causes of primary hypothyroidism are due to autoimmune thyroiditis or Hashimoto's Thyroiditis and also the over-treatment of hyperthyroidism. Hashimoto’s Thyroiditis is an autoimmune condition which occurs when the body’s immune system mistakes healthy thyroid tissues and cells as foreign and as a potential danger to the body. The immune system attacks the “invaders” resulting in the inflammation of the thyroid gland, which can eventually become permanently disabled.
This genetic disease was named after the Japanese doctor who originally characterized the inflammation of thyroid cells. An enlarged thryoid gland is almost always present in this disease. It is commonly described as a cyst-like growth in the neck (Simon, 2009). This disease occurs in about .55% of the general population. It is a permanent health condition and requires perennial treatment. Environmental factors, as well as genetic, have been shown to play a crucial role in the development of this disease. Primary hypothyroidism can also result from excessive treatment of hyperthyroidism. Hyperthyroidism occurs when the thyroid is stimulated to produce too much thyroid hormone. Treatments include medications, such as lithium and amiodarone, radioactive iodine therapy and sometimes even surgery. Studies show that over 50% of patients that receive radioactive iodine treatments for an overactive thyroid have developed permanent hypothyroidism. Other forms of treatment for overactive thyroid glands using either anti-thyroid drugs or surgery may also result in hypothyroidism (Simon, 2009). Common symptoms of primary hypothyroidism can include: fatigue, weight gain, hair loss, coarseness of hair and voice, dryness and/or roughness of skin, irritability, depression, constipation, cold intolerance, abnormality in menstrual cycles, memory loss and weakness. Each individual with hypothyroidism may experience any number of these symptoms. However for some patients, these symptoms may not occur and can even go unnoticed (Norman, 2012). Treatment for this health condition is very simple. The easiest and most effective treatment is simply taking a thyroid hormone pill (Levothyroxine) once a day, preferably in the morning. This medication is a pure synthetic form of T4 which is made in a laboratory to be an exact replacement for the T4 that the human thyroid gland normally secretes. It comes in multiple strengths, which means that an appropriate dosage can almost always be found for each patient. The dosage should be re-evaluated and possibly adjusted monthly until the proper level is established. The dose should then be re-evaluated at least annually (Norman, 2012). Secondary hypothyroidism can occur when there is a decrease in thyroid activity due to failure of the pituitary gland or hypothalamus. Causes of this type of hypothyroidism include, but are not limited to, a tumor in one of the aforementioned areas, radiation of the brain, hypertension and high cholesterol. The symptoms of secondary hypothyroidism are the same of primary hypothyroidism. However, thinning of eyebrows, decreased hearing and the slowing of speech can also occur. Treatment for secondary hypothyroidism usually depends on the severity and also the underlying cause of the condition. Treatment options can include the discontinuation of drugs that may have been the cause of the problem, thyroxine replacement therapy, and/or surgery. Hypothyroidism can also occur in newborns. In this case, the condition is referred to as Congenital Hypothyroidism. This occurs in .03% of births a year or 1 in 4000 babies. In 90% of these cases, the condition persists throughout life. In up to 85% of those cases, the thyroid gland is missing, underdeveloped, or not properly located (Simon, 2009). Temporary hypothyroidism can also occur in infants. In most cases, the causes of this stem from various immunologic, environmental, and genetic factors. If the mother has any thyroid problems they can also carry on to her baby. For example, women who have an underactive thyroid are at an increased risk of delivering babies with congenital hypothyroidism. Medications used to treat hyperthyroidism can block the production thyroid hormones. These same drugs can also cross the placenta and cause hypothyroidism in the infant (Simon, 2009). However in 20% of these cases, the causes still remain unknown. Children with temporary congenital hypothyroidism should be followed-up regularly during adolescence and adulthood for possible thyroid problems. All babies are now screened for hypothyroidism in order to prevent retardation that can occur if treatment is delayed. Symptoms of hypothyroidism in children vary depending on when the problem first develops. Most children who are born with a defect that causes congenital hypothyroidism have no obvious symptoms. Symptoms that do appear in newborns may include jaundice, noisy breathing, and an enlarged tongue. Early symptoms of undetected and untreated hypothyroidism in infants include feeding problems, failure to thrive, constipation, hoarseness, and sleepiness. Later on, symptoms in untreated children include protruding abdomens; rough, dry skin; and delayed teething. Rarely, in advanced cases, yellow raised bumps may appear under the skin, the result of cholesterol build-up. If they do not receive proper treatment in time, children with hypothyroidism may be extremely short for their age, have a puffy, bloated appearance, and have below-normal intelligence. Any child whose growth is abnormally slow should be examined for hypothyroidism (Brown, 2006). Hypothyroidism is diagnosed after the completion of both history and physical exams of the patient and by performing tests on the patient's blood. In diagnosing, blood tests measuring hormone levels are needed to make a correct diagnosis. In some cases, antibody tests are also helpful. In the physical exam, the doctor will check the heart, eyes, hair, skin, and reflexes for signs of this condition. Because symptoms of hypothyroidism can mimic those of many other conditions, blood tests for measuring levels of TSH and T4 are the only definitive way to diagnose this condition. However, the results of these blood tests can be affected by illnesses that are not thyroid related (Allahabadia, Abraham, 2009). Other ways to diagnose and/or locate signs of hypothyroidism include imaging tests. Thyroid scintigraphy can be used to determine which areas of the thyroid are producing normal amounts of TSH. In this type of test, the patient drinks a small amount of radioactive iodine and waits until the substance has passed through the thyroid. Images of a properly functioning thyroid show uniform levels of absorption throughout the gland. Overactive areas show up white, and underactive areas appear dark. Thyroid scans are more likely to be done to evaluate a goiter or thyroid nodules. They can help identify areas of the gland that may have cancer (Allahabadia, Abraham, 2009). Ultrasounds have limited value when scanning for hypothyroidism but they can visualize the thyroid and specific abnormalities, such as nodules. However, they cannot measure the thyroid gland's function. To make sure hypothyroidism is being treated properly, cholesterol levels need to be checked. Other blood tests may be performed to detect levels of calcitonin, calcium, prolactin, and thyroglobulin and to check for anemia and liver function, all of which may be affected by the health condition. Some doctors believe that because thyroid problems are so common in the elderly and thyroid hormone tests are so inexpensive, blood tests for thyroid function should be routine. Undiagnosed hypothyroidism in elderly patients can develop into a serious and even life-threatening situations (Vaidya, Pearce, 2008).
Conclusion:
Hypothyroidism, like other body complications, has developed over time due to biological factors. Although this condition cannot be cured, it can be diagnosed and treated in an abundance of ways. The differences in types of diagnosis and treatment can be varied, depending on the severity of the condition. Hypothyroidism is most commonly found in women and individuals over 50 years of age, but can also be found in children and infants. Mothers cannot easily prevent this condition from passing on to their offspring, however the gene can sometimes skip generations. Due to this factor, genetics play an important role in the occurrence of this condition. Treatment for hypothyroidism includes a number medications containing hormones and also the use of radioactive therapy. Hypothyroidism is a lifelong health condition that must be treated in order for the body to function properly. Those who do not treat this illness can suffer health complications from heart failure to mental health issues (Berber, Rehan 2012). Expectant mothers, along with their children, are now being screened for signs of the condition. Tests are also recommended for the elderly and those over the age of 50, or anyone experiencing the aforementioned symptoms.
Discussion:
Screening for congenital hypothyroidism has been taking place for just one month shy of 39 years. The birth of screening for this condition took place in April of 1974 in Quebec. Since then, it is estimated that over one million newborns are being tested yearly for hypothyroidism. Programs have been regularly established in other countries, one example being the Mexican experience(1999). The American Office of Technology Assessment concludes that screening for congenital hypothyroidism is one of the few programs in preventive medicine that has an impact on public health with a positive cost to benefit ratio of 10:1. This is the anecdotal history of screening for congenital hypothyroidism for this special issue of the journa1 (Dussault, 1999). In a 12-year longitudinal study, there was an investigation on the long-term risk of hypothyroidism in women who previously had had Postpartum Thyroid Dysfunction (PPTD). The study involved 409 women, 71 of whom had previously been diagnosed with PPTD. At the 12-year follow-up, 27 women in the PPTD group and 14 women in the non-PPTD group (38% and 4%, respectively) were found to have hypothyroidism. Based on an analysis of Odds Ratios (OR), the conclusion of the study was that within the PPTD group, women who had been diagnosed with postpartum hypothyroidism were among those at particularly high long-term risk for hypothyroidism the OR being 9:7 (Bharaktiya, 2011). Hypothryoidism for me is just an everyday occurance. I was born with this health condition. My mother’s biological mother has hypothyroidism. She passed it onto to me. It skipped over my mother and my older sister. At birth, the doctors noticed that I had unusual features, such as a short neck and an engorged tongue. They told my mother that needed to do genetic testing because I "might be small". When my mother asked if they meant I would be petite or a dwarf, they said that that was why the tests needed to be run. My mother was happy to learn that I would just be petite. At five days old, I began taking Synthroid, a synthetic form of thyroid hormones as mentioned prior. My mother would crush the pill up and incorporate it with her breast milk and feed it to me using a spoon. For the first year of my life, we would have my blood drawn bi-weekly to test my thyroid levels. As I grew, the time in between blood testing lengthened. Presently, I get tested quarterly and visit the endocrinologist bi-annually. It has taken quite some time to find a dosage that is just right. I will always live with hypothyroidism. Hopefully future my children, or their children, will not be afflicted with this health condition.
References:
Allahabadia, A. Abraham, P. (2009). Diagnosis and treatment of primary hypothyroidism. BMJ. March 26, 2009.

Berber, E. Rehan, K. (2012). Complications of Hypothyroidism. http://www.endocrineweb.com/conditions/hypothyroidism/complications-hypothyroidism Bharaktiya, S (2011). Recent studies in hypothyroidism. July 22, 2011 http://emedicine.medscape.com/article/122393-overview Brown, RS. (2006). Update of newborn screening and therapy for congenital hypothyroidism. Public Health Committee Pediatrics. June, 2006

Dugdale, DC. (2012) Symptoms of hypothyroidism http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001393/ Dussault, JH. (1999). The Anecdotal History of Screening for Congenital Hypothyroidism http://jcem.endojournals.org/content/84/12/4332.full Dussault JH, Laberge C. (1973) A new method for detection of hypothyroidism in the newborn. Proc Congress of the Canadian Society for Clinical Investigation. http://jcem.endojournals.org/content/84/12/4332.full Holt, EH. (2008) Secondary hypothyroidism http://health.nytimes.com/health/guides/disease/hypothyroidism-secondary/overview.html Norman, J. (2012) Hypothyroidism: Too Little Thyroid Hormone. October 18, 2012. http://www.endocrineweb.com/conditions/thyroid/hypothyroidism-too-little-thyroid-hormone Simon, H. (2009). Causes of hypothyroidism http://www.umm.edu/patiented/articles/what_causes_hypothyroidism_000038_2.htm

Vaidya, B & Pearce, SH. (2008). Management of hypothyroidism in adults. BMJ. July 28, 2008