The thyroid is a gland in your neck that produces hormones (TS3 and TS4) responsible for growth and overall metabolism in every cell in your body. If trouble starts with your thyroid, therefore, there are implications for whole-body imbalance.
Over-production of thyroid hormones is known as hyperthyroidism; under-production or decreased effect of thyroid hormones on body tissues is hypothyroidism, which is the more common condition. The most common cause of an imbalance of thyroid hormones is an autoimmune condition, in which the body mistakes normal cells for foreign invaders and attacks them. (1)
Causes of Underactive Thyroid
The amount of hormones that the thyroid produces is regulated (in part) by the pituitary gland that sits in your head under your brain.
Hypothyroidism is often inherited, however, the increase of disorders of the thyroid worldwide suggests that there are other factors as well.
Carcinogens and toxic compounds in the environment, including exposure to radiation, have been identified as probable causes for thyroid dysfunction. (2)
The following conditions present higher risk for hypothyroidism:
- family or personal history of autoimmune disease
- women in the post-partum period
- personal history of neck or head irradiation
- primary pulmonary hypertension
- Turner’s and Down syndromes
- medications: amiodarone, interferon-alpha, aminoglutethimide, thalidomide, sunitinib, sorafenib and lithium
- people over 65 years of age
Other causes of hypothyroidism:
- Gland damage from surgery, radiation, atrophy
- Iodine deficiency or excess (3)
- Hypothalamic or pituitary disease (4)
Autoimmune disease is responsible for about ninety percent of adult hypothyroidism. (5) Thyroid dysfunction is one of the most common endocrine disorders worldwide, affecting four to twenty percent of the population, depending on the country. (6) It’s estimated that two hundred million people have some kind of thyroid disease and almost half of them don’t know it! (7)