The Mechanisms And Causes Of Hypothyroidism

By hypothyroidism the body does not get enough thyroid hormone, or the hormones do not work effectively in the body. This causes the metabolism to slow down. When the metabolism decreases, the processes in the body do not get enough fuel and building materials, and all the body activities will therefore slow down. Energy containing nutrient will also be stored as fat, since they are not broken down.  

Serious variants of hypothyroidism are called myxedema. This is a rare condition. However, less serious, but painful variants are common.

There are several reasons for hypothyroidism, each giving a variant of the disease:

• An autoimmune reaction against the thyroid tissue can destroy the capability of the thyroid gland to produce hormones (for example Hashimoto's disease).
• Sometimes the production of T3 by conversion from T4 is impaired. The total amount of hormones may be normal in these cases, but the body is still lacking T3, and gets the symptoms of hypothyroidism.
• Iodine deficiency can cause hypothyroidism, since the thyroid hormones contain iodine. In Europe and America the food is seldom short in iodine, but bad nutrition may result in iodine deficiency.
• Surgery or radiation at the thyroid area can destroy enough tissue to cause hypothyroidism.
• Injury or disease in the pituitary or of the part of the brain controlling the pituitary may cause a decrease in secreted thyrotropin, and then the thyroid will respond by producing less of its own hormones with hypothyroidism as a result.
• Some people have symptoms of hypothyroidism even though the amount of thyroid hormone in the blood is normal. One of the symptoms is raised levels of thyrotropin, indicating that the body signals need for more thyroid hormones. This variant may be caused by conditions elsewhere in the body that make it difficult for the hormone to reach their destination in the cells. In many of these cases the immune system produces anti-bodies against the thyroid hormones. This variant is called sub-clinical hypothyroidism, and responds to the same treatment as ordinary hypothyroidism.
• Some types of food can contribute to a depressed thyroid function or aggravate hypothyroidism when eaten raw in great amounts: Brussel sprouts, broccoli, corn oil, cabbage, cauliflower, kale, kohlrabi, radishes, rutabaga, soy and turnips. By cooking these vegetables, the depressing effect is decreased.
• Factors suspected for causing hypothyroidism are: The artificial sweetener aspartame, mercury pollution, dental fillings containing mercury, fluoride and heavy metal pollution.