Hypothyroidism is a condition where the thyroid does not produce enough of the hormones that are required to maintain metabolism (Harvard School of Medicine, 2007). Introduction
Hypothyroidism is not a disease itself, but is a condition that a disease state causes (Buckley & Schub, 2008). Many of the causes of hypothyroidism are related to autoimmune conditions, where the body attacks itself, rendering the thyroid useless (Raisbeck, 2009). In fact, this is the most common cause of hypothyroidism (Raisbeck, 2009). Second to autoimmune disease is overcorrection of hyperthyroidism by surgery or radiation treatment (Walker, 2009). Thyroidectomy is the third most-prevalent cause, usually for the treatment of cancer (Walker, 2009).
Diagnosis of hypothyroidism is not always easy. Patients often present with vague symptoms, such as depression, lethargy, weight gain, sensitivity to cold, and dry skin (Harvard School of Medicine, 2007). Often, patients are treated for other disease states before the thyroid disorder is discovered and treated (Buckley & Schub, 2008). Biochemistry Description
Thyroid Stimulating Hormone (TSH) is a peptide hormone that is produced in the adrenal glands. Its purpose is to cause thyroxine (T4) and triiodothyronine (T3) to be produced by the thyroid (Harvard School of Medicine, 2007). Production of TSH is caused by the production of thyrotropin-releasing hormone (TRH) in the hypothalamus (Harvard School of Medicine, 2007).
When the levels of T3 and T4 are low, the hypothalamus releases TRH, which causes the adrenal glands to produce TSH, which will cause the thyroid to produce hormones (Raisbeck, 2009). The levels of T3 and T4 are high, TRH output is reduced, causing reduction in TSH production (Raisbeck, 2009).
The thyroid hormones are involved in metabolism in every cell of the body (Buckley & Schub, 2008). In addition to setting the basal metabolic rate, the hormones are involved in protein synthesis and...