The Signs and Symptoms of Hypothyroidism - Research Paper Example

Biochemical assessment of Thyroid diseases The thyroid gland is one amongst the endocrine glands which produce hormones that are needed to regulate the body’s physiological functions. This gland is located at the lower neck, below the voice box, and above the collarbones. It is the gland responsible for the production of the thyroid hormones which control the rate of the body’s metabolism. The endocrine glands include the following: pancreas, pituitary glands, adrenal glands, parathyroid glands, testes, and ovaries (American Academy of Otolaryngology, 2006) In order to perform a healthy rate of metabolism that is needed by the body, the thyroid gland produces the T3 (triiodothyronine) and T4 (thyroxine) hormones. When the body uses these hormones, the thyroid creates more to replace them. The pituitary gland monitors the amount of the thyroid hormones in the bloodstream and adjusts the production of its own hormone accordingly. The pituitary gland also sends this information to the thyroid gland so the latter knows how much hormone it needs to produce (Endocrine Web, 2006a) Thyroid diseases occur when the thyroid gland produces more hormones, which prompts the body to consume more energy. This disorder is called hyperthyroidism. When the thyroid gland produces fewer hormones, the body is prompted to lessen its energy consumption. This condition is called hypothyroidism (American Academy of Otolaryngology, 2006) According to the Cleveland Clinic Health Information Centre (2006), the different causes of hyperthyroidism include the following conditions: Too much iodine, which can be found in a number of drugs, especially cough syrups, can cause the thyroid gland to produce more or less hormones. Thyroiditis, a disease which can either be painless or painful, can trigger the thyroid gland to produce more hormones, thus, causing hyperthyroidism to occur in short periods of time. The painless type usually happens to women who have just given birth. Nodules, which are overactive in the thyroid. A single nodule is referred to as toxic autonomously functioning thyroid nodule. Several nodules present are referred to as toxic multi-nodular goiter. In the case of Graves’ disease, the whole thyroid gland is overactive and produces excessive quantities of hormones. This condition is referred to as diffuse toxic goiter, or enlarged thyroid gland. Based on the Clinic Health Information Centre (2006), the different causes of hypothyroidism include the following conditions: Iodine deficiency, a serious health problem which affects almost a million people globally. Iodine is needed by the thyroid gland to produce enough hormones for the body. Thyroiditis, or swelling of the thyroid gland. When this condition occurs, the amount of hormones produced by the thyroid gland is lessened. Hashimoto’s thyroiditis, a hereditary, painless thyroid disease. Postpartum thyroiditis, a temporary condition which happens to women who have just given birth. A malfunctioning thyroid gland, a condition which affects one in 4,000 newborns each year. If the condition goes untreated, the child will suffer serious mental and physical retardation. The symptoms of hyperthyroidism include severe irritability and nervousness, muscle tremors, unpredictable and infrequent menstrual periods in women, sudden weight loss, inability to sleep, enlarged thyroid, eye irritation, and sensitivity to heat. The symptoms of hypothyroidism are fatigue, heavy and frequent menstrual periods in women, severe forgetfulness, sudden weight gain, dry hair and skin, raspy voice, and sensitivity to cold (The Cleveland Clinic, 2006) Doctors perform various thyroid diagnostic tests to determine if the thyroid gland is functioning well. These tests include the T3 and T4 tests, the TSH (thyroid stimulating hormone) test, and ultrasound of the thyroid gland. The TSH test is usually done first, as it is the best measure of how well the thyroid gland functions. When the blood levels of TSH is high, the thyroid glad is under active; and when it is low, the thyroid gland is overactive (Merck, 2006a; Merck, 2006b) The TSH test is usually done prior to the T3 and T4 tests. It is done to find out if the thyroid gland is functioning well; identify the causes of an under active or overactive thyroid gland; or to check the functions of the thyroid gland in people who are receiving treatment for hyperthyroidism (WebMD, 2006) The levels of T3 hormone determine if the thyroid is functioning properly. The thyroid gland produces hormones as T4 hormones, and the body cells convert them to T3, which is considered as the more dynamic hormone between the two (MedLinePlus, 2006b) A T3 test, also called Total T3, or Free T3, is performed to determine if the thyroid gland is properly functioning. It is done primarily to aid in the diagnosis of hyperthyroidism, but it could also be done to monitor the conditions of a patient with a different thyroid problem. It is done as a follow-up to a questionable TSH test result. The T3 test determines the amount of triiodothyronine in a person’s bloodstream. About 99.7% of the total T3 found in the blood is connected to a protein, a thyroxine binding globulin (TBG), while the remaining is free. Different tests can be performed to determine either the total or free T3 hormones in a patient’s blood (American Association for Clinical Chemistry, 2006a; American Association for Clinical Chemistry, 2006b). Both T3 and T4 are carried along the blood stream by the protein TBG, but small amounts can also be found on albumin and prealbumin (University of California, 2006b; University of California, 2006a). The test is done by extracting blood from a vein in the patient’s arm or back of hand. The part of the skin which is punctured will be cleaned using an antiseptic solution, and a strong elastic band will be placed on the patient’s upper arm to increase pressure and reduce the flow of blood in the vein. A needle would then be inserted into the vein and the blood will be collected in a vial or syringe. When the blood has been extracted, the needle will be taken out, and the punctured skin will be covered to stop bleeding. For young children, the skin area, usually the sole of a foot is punctured or cut with a very sharp needle. The blood is then placed into a small glass tube called a pipette, or placed on a glass slide, a test strip, or into another small container. Bandage will be placed on the punctured part to stop any bleeding (University of California, 2006a; University of California, 2006b) The T4 test is performed in combination with the TSH test to evaluate the condition of a patient with an enlarged thyroid gland, or goiter, and to diagnose infertility among females. There are two laboratory tests that could be performed, depending on the health conditions of a patient. If a patient has autoimmune-related thyroid condition, then thyroid antibodies will also be tested along with the T4 test. It is also ordered among pregnant women with thyroid problems to find out if their fetuses have hyperthyroidism or hypothyroidism. A total T4 test is conducted to determine hyperthyroidism and hypothyroidism. Though it is a useful test, it is commonly affected by the presence of proteins in the blood which bind to the hormone. The free T4 test is a new technology, but it is not affected by proteins in the bloodstream (American Association for Clinical Chemistry, 2006a; American Association for Clinical Chemistry, 2006b). Hyperthyroidism, or hyrotoxicosis, is a condition characterised by the increased levels of thyroid hormones in the blood. It is an imbalance caused by the increased secretion of the thyroid hormones. (MedLine Plus, 2006a) This condition means an overactive thyroid gland which produces more thyroid hormones than what is required by the body. One in 50 women in the United Kingdom develops this disorder every year (British Thyroid Foundation, 2006) Hyperthyroidism may also result from the release of thyroid hormone into the peripheral circulation system even without the production of the thyroid hormones. This is commonly due to the other disparaging effects brought about by the occurrence of thyroiditis to the thyroid secondary. Hyperthyroidism can also be caused by the intentional or unintentional intake of extra volumes of thyroid hormones; in this case it is termed as thyrotoxicosis factitia (The Merck, 2006a). The common symptoms of hyperthyroidism, which include all the problems that a patient feels, are the following: occasional palpitations, intolerance to heat, irritability, nervousness, insomnia, breathlessness, frequent bowel movements, intermittent menstrual periods, and fatigue. The signs associated with this disorder, meaning those conditions which a doctor can objectively observe and evaluate, are: faster heartbeat rate, trembling hands, sudden weight loss, weakness of muscles and joints, warm but moist skin, hair loss, and glassy, staring gaze. (Endocrine Web, 2006a; Endocrine Web, 2006b). Hyperthyroidism can be diagnosed using a person’s medical history, physical examinations and several laboratory tests. When blood tests indicate that a person suffers from hyperthyroidism, he/she will be prescribed to go through a radioactive iodine uptake test and a thyroid scan (MayoClinic, 2004) The different forms of hyperthyroidism include Grave’s diseases (toxic goiter), toxic nodular goiter, and thyroiditis. Grave’s disease is believed to be caused by an antibody that stimulates the thyroid gland excessively, causing increased hormone production. This condition is considered an autoimmune disorder and is common among young and middle-aged women. It is also hereditary and runs among families. The symptoms of Grave’s disease are similar to that of hyperthyroidism, but there are three more symptoms which are unique to this disorder. These are: goiter (bulging neck), bulging eyes, and thick skin in the lower leg area. Grave’s disease is also known as diffuse toxic goiter and is often characterised by the presence of goiter and/or exophthalmos and/or pretibial myxedema. It is the most common from of hyperthyroidism and is known to recur and relapse after treatment (Merck, 2006a; Merck, 2006b). Grave’s disease is classified as a type II hypersensitive autoimmune disorder and is characterized by the synthesis of ‘auto antibodies’ that readily bind with the TSH receptor found on the thyroid’s follicular cells (these are cells in the thyroid that is responsible for the production of thyroid hormone). When these ‘auto antibodies’ bind to the TSH receptors, they elicit the same action as TSH itself which will lead to an increase in the production of thyroid hormone. Auto antibodies can also invade optic cell and when this happens, it is known as infiltrative opthalmopathy, thyroid eye disease or euthyroid Grave’s disease. This is caused by the expression of the TSH receptors on eye tissues in the retro-orbital area. The cause of auto antibody synthesis is still relatively unknown but it is speculated that viral infection triggers this synthesis. Also it seems that Grave’s disease has a genetic predisposition and that some people are more genetically inclined to produce auto antibodies than anyone else (Wikipedia, 2006). Toxic nodular goiter is a disorder wherein one or more nodules of the thyroid gland become hyperactive. These nodules then become benign tumors. The causes of this disorder are still unknown. Thyroiditis is a temporary condition, one which is usually followed by hypothyroidism (University of Virginia, 2006) The treatment of hyperthyroidism varies depending on the patient’s physical condition and the symptoms associated with the disease. Hyperthyroidism is usually dealt with antithyroid drugs, like radioactive iodine, which is used to destroy the thyroid and stop the excessive production of thyroid hormones; and thyroidectomy, a surgical operation to completely remove the thyroid gland. Usually, if the thyroid has been removed through surgery, the patient will be given replacement hormones to sustain him/her for life. (MedLine Plus, 2006a) Another form of treatment may be the use of beta-blocking drugs which stop the effects of thyroid hormones on the body. These medications help make the patient feel better and do not change the levels of thyroid hormones in the body (University of Virginia, 2006) The two leading antithyroid drugs in the United States are methimazole (Tapazole) and propylthiouracil (PTU). These drugs block or stop the production of thyroid hormones. PTU stops the conversion of T4 to T3, which is a more active hormone. The downside of these drugs is the occasional suppression of while cells production in the bone marrow. When patients taking methimazole start to develop fever, sore throat, and other infections, they should seek medical help immediately (MedicineNet, 2006). Hypothyroidism is another thyroid disease that is essentially the reverse of hyperthyroidism. It’s most common form is primary hypothyroidism which is believed to be an autoimmune disease like Grave’s disease and is a result of an early case of Hashimoto’s thyroiditis. Symptoms often include goitre or in later forms of disease the thyroid may shrink and become fibrous which has little or no hormonal functions at all (Merck, 2006a; Merck, 2006b). Another common form of hypothyroidism is post-therapeutic hypothyroidism which happens after radioactive thyroid therapy, after a surgery done due to hyperthyroidism or during the intake of excess doses of the drugs propylthiouracil, methimazole, and iodide after therapy. This is considered to be a normal and temporal condition after such medical treatments and the normal function of the thyroid will go back as it is (Merck, 2006a; Merck, 2006b). The signs and symptoms of hypothyroidism are: dull facial expressions, hoarse voice and slow speech, facial puffiness and periorbital swelling due to infiltration of mucopolysaccharides hyaluronic acid and chondroitin sulphate in the eye, cold intolerance, drooping eyelids because of decreased adrenergic drive, sparse or balding hair , and finally coarse, dry, scaly, and thick skin. A slight gain in weight may be experienced by the person suffering from hyporthyroidism due to the decreased metabolism. Intellectual impairment is evident as well as short-term memory loss and memory lapses. Depression may also be present and mild cases of psychosis are common for hypothyroid patients. Hypothyroid patients are usually subjected to behaviour modification and depression management therapy to maintain their emotional stability (Merck, 2006a; Merck, 2006b). Treatment of hypothyroidism includes the intake of synthetic hormone preparations such as T4 (L-thyroxine), triiodothyronine (liothyronine), combinations of the two synthetic hormones, and even desiccated animal thyroid. The average maintenance dosage is 75 to 125 µg/day, but initial doses must be much lower, especially for the elderly, those with heart disease, and for those persons with long-standing or severe cases of hypothyroidism (except for persons with myxedema coma) (Merck, 2006a; Merck, 2006b). Reference List American Academy of Otolaryngology. 2006. Thyroid Gland. American Academy of Otolaryngology − Head and Neck Surgery. [Online] Available: http://www.entnet.org/healthinfo/thyroid/thyroid_gland.cfm [2 May 2006] American Association for Clinical Chemistry. 2006a. T3. American Association for Clinical Chemistry. [Online] Available: http://www.labtestsonline.org/understanding/analytes/t3/sample.html [2 May 2006] American Association for Clinical Chemistry. 2006b. T4. 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