Question: What is (are) Hypothyroidism ?
Answer: Hypothyroidism is a disorder that occurs when the thyroid gland does not make enough thyroid hormone to meet the bodys needs. Thyroid hormone regulates metabolismthe way the body uses energyand affects nearly every organ in the body. Without enough thyroid hormone, many of the bodys functions slow down. About 4.6 percent of the U.S. population age 12 and older has hypothyroidism.1
Source: NIDDK

Question: What causes Hypothyroidism ?
Answer: Hypothyroidism has several causes, including - Hashimotos disease - thyroiditis, or inflammation of the thyroid - congenital hypothyroidism, or hypothyroidism that is present at birth - surgical removal of part or all of the thyroid - radiation treatment of the thyroid - some medications Less commonly, hypothyroidism is caused by too much or too little iodine in the diet or by abnormalities of the pituitary gland. Hashimotos Disease Hashimotos disease, also called chronic lymphocytic thyroiditis, is the most common cause of hypothyroidism in the United States.1 Hashimotos disease is a form of chronic inflammation of the thyroid gland. Hashimotos disease is also an autoimmune disorder. Normally, the immune system protects the body against foreign invaderssuch as viruses and bacteriathat can cause illness. But in autoimmune diseases, the immune system attacks the bodys own cells and organs. With Hashimotos disease, the immune system attacks the thyroid, causing inflammation and interfering with its ability to produce thyroid hormones. More information is provided in the NIDDK health topic, Hashimotos Disease. Thyroiditis Thyroiditis causes stored thyroid hormone to leak out of the thyroid gland. At first, the leakage raises hormone levels in the blood, leading to hyperthyroidismwhen thyroid hormone levels are too highthat lasts for 1 or 2 months. Most people then develop hypothyroidism before the thyroid is completely healed. Several types of thyroiditis can cause hyperthyroidism followed by hypothyroidism: - Subacute thyroiditis. This condition involves painful inflammation and enlargement of the thyroid. Experts are not sure what causes subacute thyroiditis, but it may be related to a viral or bacterial infection. The condition usually goes away on its own in a few months. - Postpartum thyroiditis. This type of thyroiditis develops after a woman gives birth. For more information, see the section titled What happens with pregnancy and thyroid conditions? - Silent thyroiditis. This type of thyroiditis is called silent because it is painless, as is postpartum thyroiditis, even though the thyroid may be enlarged. Like postpartum thyroiditis, silent thyroiditis is probably an autoimmune condition and sometimes develops into permanent hypothyroidism. Congenital Hypothyroidism Some babies are born with a thyroid that is not fully developed or does not function properly. If untreated, congenital hypothyroidism can lead to mental retardation and growth failure. Early treatment can prevent these complications, so most newborns in the United States are screened for hypothyroidism. Surgical Removal of the Thyroid When part of the thyroid is removed, the remaining part may produce normal amounts of thyroid hormone, but some people who have this surgery develop hypothyroidism. Removal of the entire thyroid always results in hypothyroidism. Part or all of the thyroid may be surgically removed as a treatment for - hyperthyroidism - a large goiter, which is an enlarged thyroid that may cause the neck to appear swollen and can interfere with normal breathing and swallowing - thyroid nodules, which are noncancerous tumors, called adenomas, or lumps in the thyroid that can produce excess thyroid hormone - thyroid cancer Radiation Treatment of the Thyroid Radioactive iodine, a common treatment for hyperthyroidism, gradually destroys the cells of the thyroid. Most people who receive radioactive iodine treatment eventually develop hypothyroidism. People with Hodgkins disease, other lymphomas, and head or neck cancers are treated with radiation, which can also damage the thyroid. Medications Some drugs can interfere with thyroid hormone production and lead to hypothyroidism, including - amiodarone, a heart medication - interferon alpha, a cancer medication - lithium, a bipolar disorder medication - interleukin-2, a kidney cancer medication
Source: NIDDK

Question: What are the symptoms of Hypothyroidism ?
Answer: Hypothyroidism has many symptoms that can vary from person to person. Some common symptoms of hypothyroidism are - fatigue - weight gain - a puffy face - cold intolerance - joint and muscle pain - constipation - dry skin - dry, thinning hair - decreased sweating - heavy or irregular menstrual periods and impaired fertility - depression - slowed heart rate However, hypothyroidism develops slowly, so many people dont notice symptoms of the disease. Symptoms more specific to Hashimotos disease are a goiter and a feeling of fullness in the throat. Hypothyroidism can contribute to high cholesterol, so people with high cholesterol should be tested for hypothyroidism. Rarely, severe, untreated hypothyroidism may lead to myxedema coma, an extreme form of hypothyroidism in which the bodys functions slow to the point that it becomes life threatening. Myxedema requires immediate medical treatment.
Source: NIDDK

Question: How to diagnose Hypothyroidism ?
Answer: Many symptoms of hypothyroidism are the same as those of other diseases, so hypothyroidism usually cannot be diagnosed based on symptoms alone. With suspected hypothyroidism, health care providers take a medical history and perform a thorough physical examination. Health care providers may then use several blood tests to confirm a diagnosis of hypothyroidism and find its cause: TSH test. The ultrasensitive TSH test is usually the first test a health care provider performs. This test detects even tiny amounts of TSH in the blood and is the most accurate measure of thyroid activity available. Generally, a TSH reading above normal means a person has hypothyroidism and a reading below normal means a person has hyperthyroidism. Mildly elevated TSH without symptoms indicates subclinical hypothyroidism. Some health care providers treat subclinical hypothyroidism immediately. Others prefer to leave it untreated but monitor their patients for signs that the condition is worsening. Health care providers may conduct additional tests to help confirm the diagnosis or determine the cause of hypothyroidism. T4 test. This test measures the actual amount of circulating thyroid hormone in the blood. In hypothyroidism, the level of T4 in the blood is lower than normal. Thyroid autoantibody test. This test looks for the presence of thyroid autoantibodies. Most people with Hashimotos disease have these antibodies, but people whose hypothyroidism is caused by other conditions do not. More information about testing for thyroid problems is provided in the NIDDK health topic, Thyroid Tests.
Source: NIDDK

Question: What are the treatments for Hypothyroidism ?
Answer: Health care providers treat hypothyroidism with synthetic thyroxine, a medication that is identical to the hormone T4. The exact dose will depend on the patients age and weight, the severity of the hypothyroidism, the presence of other health problems, and whether the person is taking other drugs that might interfere with how well the body uses thyroid hormone. Health care providers test TSH levels about 6 to 8 weeks after a patient begins taking thyroid hormone and make any necessary adjustments to the dose. Each time the dose is adjusted, the blood is tested again. Once a stable dose is reached, blood tests are normally repeated in 6 months and then once a year. Hypothyroidism can almost always be completely controlled with synthetic thyroxine, as long as the recommended dose is taken every day as instructed.
Source: NIDDK

Question: What to do for Hypothyroidism ?
Answer: - Hypothyroidism is a disorder that occurs when the thyroid gland does not make enough thyroid hormone to meet the bodys needs. Thyroid hormone regulates metabolism. Without enough thyroid hormone, many of the bodys functions slow down. - Hypothyroidism has several causes, including - Hashimotos disease - thyroiditis - congenital hypothyroidism - surgical removal of part or all of the thyroid - radiation treatment of the thyroid - some medications - Hypothyroidism has many symptoms that can vary from person to person. Some common symptoms of hypothyroidism are fatigue, weight gain, cold intolerance, constipation, impaired fertility, and depression. - Women are much more likely than men to develop hypothyroidism. - Women with hypothyroidism should discuss their condition with their health care provider before becoming pregnant. - Hypothyroidism can almost always be completely controlled with synthetic thyroxine, as long as the recommended dose is taken every day as instructed.
Source: NIDDK