There are a number of reasons why a person can develop hypothyroidism. Hypothyroidism is a condition in which the thyroid gland does not produce sufficient amounts of hormones necessary for a variety of metabolic processes. In most cases, the underlying hypothyroidism cause is a problem with the thyroid gland itself.
In a few cases, it may be a problem in the pituitary gland or the brain, which both play a part in governing thyroid gland activity. The brain signals the pituitary gland to make a hormone called TSH (thyroid stimulating hormone). TSH, in turn, signals the thyroid gland to produce hormones. Under normal conditions, thyroid hormones, specifically thyroxine (T-4) and triiodothyronine (T-3) regulate metabolism, control body temperature, and govern heart rate.
Thyroid hormones are also involved in protein production and in regulation of blood calcium levels. The inability of the thyroid gland to make enough hormones is what causes hypothyroidism. The condition compromises many processes in the body. If you are trying to find out what causes hypothyroidism - that is, what makes the thyroid gland stop producing enough hormones - you may be surprised at the list of possibilities.
Causes of Hypothyroidism
Hashimoto's Thyroiditis, treatments for hyperthyroidism (overactive thyroid) or thyroid tumors, radiation of the head or neck to treat cancer, and drug interference can cause low thyroid function.
Hashimoto's Thyroiditis- Hashimoto's Thyroiditis, a malfunction of the immune system that causes the body to turn against healthy thyroid cells, is the most common hypothyroidism cause. This autoimmune condition causes loss of thyroid cells due to repeated inflammation from the immune response. Eventually, enough cells are lost to cause the thyroid gland to become ineffective, and it no longer produces sufficient amounts of thyroid hormones.
Radiation Treatments - Other conditions that damage the thyroid gland and cause a significant loss of thyroid cells are radiation treatments of the head and neck and surgical removal of all or part of the thyroid gland, which may be necessary because of over-activity (hyperthyroidism) or thyroid tumors.
Medications - In some cases, medications inhibit production of thyroid hormones and cause hypothyroidism. Examples are lithium, amiodarone, and propylthiouracil.
In addition to the three causes mentioned above, hypothyroidism can be the result of certain changes within the body. Visit what causes hypothyroidism to learn more about it.
