Thyroid

Hypothyroidism results when the thyroid gland fails to produce enough hormones. Hypothyroidism may be due to a number of factors, including:

• Autoimmune disease: The most common cause of hypothyroidism is an autoimmune disorder known as Hashimoto’s thyroiditis. Autoimmune disorders occur when your immune system produces antibodies that attack your own tissues. Sometimes this process involves your thyroid gland.
• Over-response to hyperthyroidism treatment: People who produce too much thyroid hormone (hyperthyroidism) are often treated with radioactive iodine or anti-thyroid medications. The goal of these treatments is to get thyroid function back to normal. But sometimes, correcting hyperthyroidism can end up lowering thyroid hormone production too much, resulting in permanent hypothyroidism.
• Thyroid surgery: Removing all or a large portion of your thyroid gland can diminish or halt hormone production. In that case, you’ll need to take thyroid hormone for life.
• Radiation therapy: Radiation used to treat cancers of the head and neck can affect your thyroid gland and may lead to hypothyroidism.
• Medications: A number of medications can contribute to hypothyroidism. One such medication is lithium, which is used to treat certain psychiatric disorders. If you’re taking medication, ask your doctor about its effect on your thyroid gland.