Hypothyroidism is a condition in which the body lacks sufficient thyroid hormone. Since the main purpose of thyroid hormone is to "run the body's metabolism", it is understandable that people with this condition will have symptoms associated with a slow metabolism. Over five million Americans have this common medical condition. If you want to know more about this, check out Symptoms for Hypothyroidism. In fact, as many as ten percent of women may have some degree of thyroid hormone deficiency. Women, especially those older than 50, are more likely to have hypothyroidism. Hypothyroidism upsets the normal balance of chemical reactions in your body. It seldom causes symptoms in the early stages, but over time, untreated hypothyroidism can cause a number of health problems, such as obesity, joint pain, infertility and heart disease. Hypothyroidism is a common endocrine disorder resulting from deficiency of thyroid hormone. It usually is a primary process in which the thyroid gland produces insufficient amounts of thyroid hormone. It can also be secondary, that is lack of thyroid hormone secretion due to the failure of either adequate thyrotropin (ie, thyroid-stimulating hormone [TSH]) secretion from the pituitary gland or thyrotropin-releasing hormone (TRH) from the hypothalamus (secondary or tertiary hypothyroidism). Causes About three percent of the general population is hypothyroid. Factors such as iodine deficiency or exposure to Iodine-131 (I-131) can increase that risk. There are a number of causes for overt hypothyroidism. Historically, and still in many developing countries, iodine deficiency is the most common cause of hypothyroidism worldwide. In iodine-replete individuals, hypothyroidism is mostly caused by Hashimoto's thyroiditis, or by a lack of the thyroid gland or a deficiency of hormones from either the hypothalamus or the pituitary. Symptoms of Hypothyroidism The symptoms of hypothyroidism vary widely, from no symptoms to marked symptoms, to, rarely, life-threatening symptoms. The symptoms of hypothyroidism are notorious for their nonspecific nature and for the way in which they mimic many of the normal changes of aging. The extent of symptoms depends on the severity of the hormone deficiency and the speed with which the deficiency developed. Usually, symptoms are milder when hypothyroidism develops gradually. Symptoms occur slowly over time. At first you might not notice them, or you might mistake them for normal aging. See your doctor if you have symptoms like these that get worse or won't go away. Treatment The purpose of treatment is to replace the deficient thyroid hormone. Levothyroxine is the most commonly used medication. The lowest dose effective in relieving symptoms and normalizing the TSH is used. Life-long therapy is needed. Medication must be continued even when symptoms subside. Thyroid hormone levels should be monitored yearly after a stable dose of medication is determined. With the exception of certain conditions, the treatment of hypothyroidism requires life-long therapy. Before synthetic levothyroxine (T4) was available, desiccated thyroid tablets were used. Desiccated thyroid was obtained from animal thyroid glands, which lacked consistency of potency from batch to batch. Presently, a pure, synthetic T4 is widely available. Therefore, there is no reason to use desiccated thyroid extract. For more info, visit this website.