Thyroid Disorders

Student Projects for Biol. 2402 - Anatomy & Physiology
Project Members: Jo Lynn, Melissa, Misty & Judi


Before you do any of the following below see the latest info on treatment of the thyroid at:

Untreated Allergies causes Many Illness, Autoimmune Diseases, Hypothyroidism, Cancer and Ultimately, Death

Treatment for hypothyroidism should be individualized for every person. Decisions about treatment require consideration of factors including the patients’ general health and all other medications they are currently taking. Conditions that can cause abnormal thyroid test are medications for heart conditions, some narcotics, and patients with severe physical illnesses. Hypothyroidism is the simplest form of thyroid disease to treat. Simple goiter and Hashimoto thyroiditis are the two most common thyroid disorders and discussion of their treatments follow. Hypothyroidism may be associated with other autoimmune such as diabetes mellitus and Graves's disease.


Iodine is an essential component of the thyroid hormone and needs to be supplied by the diet. Thus, simple goiter is prevalent in areas of the world where iodine intake is insufficient. Iodized salt or iodine supplements can greatly reduce the incidence of simple goiter disease. Where iodine intake is sufficient Hashimoto seems to be the most common cause of goiter.


The most popular form of treatment is hormone replacement therapy. It replaces the thyroid hormones that your body cannot produce on its own. Thyroxine (T4), is given for three reasons: 1. it shrinks the goiter by lowering the production of TSH by the pituitary gland; 2. it anticipates the development of thyroid failure and the resulting low levels of thyroid hormone since the disease will progress with time; 3. it usually has an effect on blood lymphocytes which cause the damage and destruction in the thyroid gland. Most patients with Hashimoto have a diffused and symmetrically enlarged thyroid gland; therefore, larger doses of (T4) are usually prescribed to initially shrink the goiter. With this treatment the gland commonly shrinks over a period of 6-18 months.


Doctors usually prescribe synthetic thyroxine (T4) or a man-made thyroid hormone called levothyroxine sodium. The usual dose of levothyroxine sodium is (0.05 - 0.2 mg daily). It may take months to find the proper dose of medication for the individual. After each dosage adjustment, the patient's TSH level should be measured. When the TSH level is in the normal range, it means the dose of levothyroxine sodium is correct. The oral medication must be taken everyday and the cost is approximately $60.00 -$80.00 a year.

It is important not to switch brands without notifying your doctor, because even the identical dose of another brand may not deliver the identical amount of levothyroxine sodium. Your doctor will monitor your thyroid function at least once a year. The amount of medication taken can change as you age because less hormone therapy is needed the older you are. After a person has been on the medication for approximately six weeks he/she should feel better. Even if your symptoms subside, it is important to continue taking your medication because your symptoms will likely return. Patients should be advised that treatment is for life.


In the past, before most patients were switched to synthetic thyroxine (T4), they used a desiccated (dried & powered) animal thyroid therapy. It is rarely prescribed today because it also contains triiodothyronine (T3), a rapidly acting thyroid hormone which produces more variable blood levels than pure thyroxine preparations. Each batch may vary in potency because it comes from animal thyroid glands, which can vary in their thyroid hormone content.


If you are not taking enough thyroid hormone treatment, you may experience symptoms such as sluggishness, mental dullness, or feeling cold. If you are taking too much medication, your symptoms may mimic an overactive thyroid such as nervousness or insomnia. You also need to be aware that prolonged usage of T4 treatment could increase the risk of bone demineralization in patients of all ages.


Hashimoto's acute thyroiditis is the most common type of thyroid gland failure and is an inherited condition. Examinations of family members may reveal other individuals with thyroid problems. Good news is, patients with thyroid disease can usually be successfully treated.


Treating Graves’ disease means controlling the activity of the thyroid gland by keeping its activity level at a normal production. There are several different treatments available to control hormone overproduction from the thyroid gland. These treatments include beta-blockers, antithyroid drugs, radioactive iodine and surgery.


Metoprolol, Atenolol, Nadolol and Propranolol are some of many beta-blockers used at the initial diagnosis of Graves’ disease. Until the thyroid gland is under control, physical symptoms such as a rapid heart rate, sweating and anxiety can be treated. Beta-blockers lowers the heart rate and blood pressure by affecting the transmission of nerve impulses from the brain to certain parts of the body; therefore, asthmatics, diabetics and heart patients should avoid using these drugs. Beta-blockers cannot treat the disease but are used in preparation for surgery and/or to get the thyroid under control for more long-term treatments.


Methimazole, more commonly known as Tapazole, and Propylthiouracil are antithyroid medicines which reduce the use of iodine by the body in the production of thyroid hormones. Antithyroid medications only effect the thyroid hormone level at the time treatment has begun. These drugs are taken consistently on a daily basis for an extended period of time (months to years) to maintain its level in the blood. Even if disease symptoms begin to subside after four-to-six weeks of treatment, drug therapy will need to be continued until physician indicates otherwise. There is a chance of remission from six months to lifetime after drug therapy is halted. Patients who are children, young adults or those who have a mild form of hyperthyrodism more commonly use these drugs.

Side effects of antithyroids range from an allergic reaction, such as a rash, to a decrease in the neutrophils of your white blood cells. Anyone taking these drugs begins to suffer from a sore throat and fever should immediately stop taking the drug and request a blood test for white blood cell count to prevent a more serious to life-threatening infection. Pregnant women can take these drugs but only in low dosages. They can also breast feed but the infant must have his/her thyroid checked on a regular basis.


Radioactive iodine is the most common and fully effective treatment for Graves’ disease especially in older adults. The treatment comes in a form of a capsule and taken orally so the iodine can travel from the stomach to the bloodstream and directly to the thyroid gland for elimination. The decay will be disposed of through urine output or it will be transformed into a nonradioactive state. This can take several weeks; therefore, beta-blockers may be taken during this time period to control the thyroid gland. Hypothyroidism, the underproduction of thyroid hormones, can occur due to the elimination of the thyroid gland. The patient is then treated with hormone replacement therapy.

The amount of radioactive iodine given is determined by the size of the enlarged thyroid. If there is no improvement after three to six months, a second larger dose will be given and a larger third dose if necessary. If after three treatments there is no success, surgery will be advised. Pregnancy is discouraged during this treatment as radiation to the fetus can be harmful.


SURGERY: Thyroidectomy

Surgery (partially removal of the thyroid gland) is a permanent treatment option. For patients with extremely enlarged thyroid glands, patients with reoccuring hyperthyroidism and patients who cannot or choose not to engage in any of the aforementioned treatments, surgery is their only option. Before surgery can be performed, Graves’ must be controlled by beta-blockers or antithyroid medications for about six weeks. Nonradioactive iodine will also be given a few days before surgery to help reduce the amount of blood supply to the thyroid gland. Once surgery is completed, the function of the remaining gland may be reduced below normal levels. Therefore, thyroid hormone replacement therapy for hypothyroidism may be necessary depending on the amount of thyroid gland left to produce a normal amount of hormones.


Treatment for an underproductive thyroid due to surgery or radioactive iodine therapy is taken in the form of a tablet usually for life. A levothyroxine tablet is a form of the thyroid hormone and it must be taken on a daily basis. Common brand names of levothyroxine are Levoxyl or Levothroid just to name a few. Once treatment begins, it may take several weeks before the patient feels normal. Treatment should not be stopped no matter how good the patient feels unless directed by a physician. The amount of levothyroxine administered depends on the patient’s needs which can change over a period of time; therefore, tests for hormone levels must be taken regularly.

Pregnant women can be treated during pregnancy without harm to the fetus but the dosage may need to be changed during and after pregnancy. Breast feeding is discouraged as the hormone can be passed to the baby through the milk, but there is no known side effects in infants who were nursed by a mother undergoing thyroid replacement therapy.


The two major types of cancer are differentiated and follicular. Differentiated makes up approximately ninety percent of all thyroid cancers. Papillary thyroid cancer makes up seventy-five percent of all cancers, with follicular cancer making up the remaining fifteen percent.

Papillary thyroid cancer has a better prognosis than follicular thyroid cancer, it is considered curable and is often treated with Radioiodides. It metastisizes slower and once killed with I131 the patient is given hormone replacement therapy. Follicular thyroid cancer is less suceptible to Radioiodides and sometimes must be removed surgically in a procedure called a thyroidectomy. These patients will begin hormone replacement therapy as well. The patient will most likely begin a low iodide diet. Some foods that contain extremely high levels of iodide per serving are, shell fish, dairy products, and tea should be avoided.


A new type of treatment, not yet being tested on humans, is gene therapy. Using thyroglobulin gene promoter (TG) which is cell specific for thyroid follicular cell and differentiated thyroid cancer cells. Studies found that TG can be used as a maker to detect thyroid cancer. Studies have indicated that the cells could be infected with the herpes simplex virus 1 thymidne kinase gene or (HSV[1]TK). After infection one hundred percent of the cells were susceptible to erradication by ganciclovir administration. Though still in the experimental stages this treatment offers great possibilities for the future.



Once an infant is identified with by a screening program, a physician examination for physical symptoms and a serum free thyroxine and TSH level tests should be performed for confirmation of the . There are several possible reasons for a false positive, so a recheck is necessary. Therapy with levothyroxine should begin without delay after the blood test, and before the results are obtained. If the tests come back normal, therapy is discontinued. Four weeks are required for serum levels to reach a steady state and suppression of elevated TSH even longer. The usual starting dosage of levothyroxine daily is 10g. per kg. usually equivalent to 0.025mg. The tablets can be easily crushed and added to cereal or formula. Thyroxine and TSH levels should be checked monthly during the first year, quarterly the second year and bi-annually thereafter. Dosage increases of 0.0125mg. (1/2 the 0.025mg. tablet) should be initiated as indicated and level rechecks one month after the increase.

Even with adequate diagnosis and therapy some children with congenital hypothyroidism have lower than expected IQs. Severity has a prenatal influence on brain development. Thyroxine seems to be the active hormone with respect to neurological development in the fetus. Despite evidence that maternal thyroxine contributes to fetal thyroxine in the later weeks of pregnancy maternal transfer seems insufficient for fetal requirements if hypothyroidism is severe.


Pregnant women with Graves’ disease or a "history" of Graves’ may transfer IgG thyroid stimulating immunoglobulins (TSI) to the fetus. Elevated free thyroxine level, low TSH level and positive TSI can confirm the diagnosis when symptoms are present. Treatment with propylthiouracil, 5 to 10 mg per kg per day, or methimazole, 0.5 mg per kg per day is the standard. Prednisone maybe required to stabilize a severely ill infant if they are thyrotoxic. As the thyroxine levels become suppressed, levothyroxine will be given to maintain normal thyroxine and TSH levels. Normally after 6 months the antithyroid medication and levothyroxine may be discontinued.

Congenital hypothyroidism and Graves’ disease are conditions that might best be referred to a pediatric endocrinologist after confirmation of the diagnosis.


Applied Medical Informatics Inc., Orbis-AHCN, L.L.C. "Graves’ Diseases". Available: (January 28, 1998).

Applied Medical Informatics Inc., Orbis-AHCN, L.L.C. "Thyroid Hormones - Oral". Available: (March 29, 1998).

Barden, MD, Wayne C., "Diffuse Nontoxic and Multinodular Goiter." Current Therapy in Endocrinology and Metabolism. Ed. Susan M. Gay and Lynne Gery. Fifth Edition. New York: Mosby, 1994: 99-107.

"Chronic Thyroiditis (Hashimoto's disease)." 1997. Online. Applied Medical Infomatics. Available: (06 February 1998).

"Hypothyroidism." 1996. Online. The American Thyroid Association. Available: (06 February 1998).

Knoll Pharmaceutical Company, "Treating Your Thyroid Disorder." Hypothyroidism and Your Health. Mount Olive: Knoll Pharmaceutical Company, 1997: 22-25.

Levy, Richard. (1993). Hypothyroidism in Infancy and Childhood. Available:

Marble, Michelle. Tissue targeted therapy for metastatic thyroid carcinoma. In Cancer Weekly Plus Feb 10 1997, p5(2).

McPhee, MD, Stephen J., Papadakis, MD, Maxines A., Tierney, Jr., MD, Lawrence M., "Thyroiditis." Current Medical Diagnosis & Treatment. Ed. Shelley Reinhardt. Thirty-fifth Edition. Stanford: Appleton & Lange, 1996: 997-998.

Mikkelsen, Alana, "Unmasking Thyroid Disease." 1996. Online. Stanford Medicine. Available: (06 February 1998).

Pediatric Endocrinology: a Clinical Guide. 2d ed rev. New York: Dekker, 1990.

Pediatrics: Endocrinology. New York: American Academy of Pediatrics Committee on Public Health, 1993: 1203-1209.

A San Francisco Bay Area Medical Group. "Endocrine Metabolic consultants." 12 Jan. 1998. Available: (28 Jan 1998)

Sim, M.D., Ida, Division of General Internal Medicine, Stanford University, "Hyperthyroidism". Available: (January 17, 1998).

TFA. "Graves’ Disease". Available: (January 17, 1998).

Thyroid Foundation of America, "Healthtouch Online". Available: (March 29, 1998).

Thyroid Foundation of Canada, "Health Guides on Thyroid Disease #6 ‘Graves’ Hyperthyroidism (Thyrotoxicosis)’. Available: thyroid/Guides/HG06.html (January 17, 1998).

"Thyroiditis." 1996. Online. Thyroid Foundation of Canada. Available: (17 January 1998).

Tierney, Jr., MD, Lawrence, McPhee, MD, Stephen J., Papadakis, MD, Maxines A. with Associated Authors, Endocrinology" Current Medical Diagnosis and Treatment, Thirty-fifth Edition,1996, pages 991-993.

Tryniszewski, RN, MSN, Cindy, "Graves’ Disease", Everything You Need To Know About Diseases 1996, pages 455-457.

Utiger, Robert. New England Journal of Medicine.vol.332.0028-4793 (1995): 183-185.

Wells, Samuel A., Jr. Recent advances in the treatment of thyroid cancer. (Editorial). In Ca Sept-Oct 1996, v46, n5, p258(3).

Annette Nay, Ph.D.


Search This Website
Search The Web