Hypothyroidism, also known as underactive thyroid, is a condition where the thyroid gland does not create enough of a thyroid hormone called thyroxine. People are hypothyroid if they have too little thyroid hormone in the blood. Here is a list of the common causes of hypothyroidism that you should know.
1. Autoimmune Disease
People who develop a particular inflammatory disorder known as Hashimoto’s thyroiditis have the most common cause of hypothyroidism. Autoimmune disorders occur when your immune system produces antibodies that attack your own tissues. Sometimes this process involves your thyroid gland.
Scientists aren’t sure why the body produces antibodies against itself. Some think a virus or bacterium might trigger the response, while others believe a genetic flaw may be involved. Most likely, autoimmune diseases result from more than one factor. But however it happens, these antibodies affect the thyroid’s ability to produce hormones.
2. Treatment For Hyperthyroidism
If you have had radiation therapy and have hypothyroidism, or if your thyroid gland has been removed, you will most likely need treatment from now on. If your hypothyroidism is caused by Hashimoto’s thyroiditis, you might also need treatment from now on. Sometimes, thyroid gland function returns on its own in Hashimoto’s thyroiditis. People with hyperthyroidism are often treated with radioactive iodine or anti-thyroid medications to reduce and normalize their thyroid function. However, in some cases, treatment of hyperthyroidism can result in permanent hypothyroidism.
3. Thyroid Surgery
Surgery is a treatment option for hyperthyroidism, but it’s not as commonly used as antithyroid medications or radioactive iodine. Thyroid surgery is known as a thyroidectomy and involves the partial or total removal of the thyroid gland. For some types of hyperthyroidism, such as from a solitary toxic adenoma, surgery entails partial removal of the half of your thyroid gland with the adenoma. For nearly all other types of hyperthyroidism, including Graves’ disease, the surgery is a nearly total thyroidectomy.
4. Radiation Therapy And Medications
Radiation used to treat cancers of the head and neck can affect your thyroid gland and may lead to hypothyroidism. A number of medications too can contribute to hypothyroidism. One such medication is lithium. Treating certain cancers, such as lymphoma, requires radiation to the neck. Radiation damages the cells in the thyroid. This makes it more difficult for the gland to produce hormone.
5. Congenital Disease
Some babies are born with a defective thyroid gland or no thyroid gland. In most cases, the thyroid gland didn’t develop normally for unknown reasons, but some children have an inherited form of the disorder. Congenital hypothyroidism is a condition of thyroid hormone deficiency present at birth. Approximately 1 in 4000 newborn infants have a severe deficiency of thyroid function, while even more have mild or partial degrees. If untreated for several months after birth, severe congenital hypothyroidism can lead to growth failure and permanent intellectual disability.
6. Pituitary Disorder
The pituitary gland is a tiny organ, the size of a pea, found at the base of the brain. As the “master gland” of the body, it produces many hormones that travel throughout the body, directing certain processes or stimulating other glands to produce other hormones. A relatively rare cause of hypothyroidism is the failure of the pituitary gland to produce enough thyroid-stimulating hormone. It is usually because of a benign tumor of the pituitary gland.
When a woman is pregnant, her body needs enough thyroid hormone to support a developing fetus and her own expanded metabolic needs. Healthy thyroid glands naturally meet increased thyroid hormone requirements. If someone has Hashimoto’s thyroiditis or an already overtaxed thyroid gland, thyroid hormone levels may decline further. So, women with an undetected mild thyroid problem may suddenly find themselves with pronounced symptoms of hypothyroidism after becoming pregnant.
Some women develop hypothyroidism during or after pregnancy, often because they produce antibodies to their own thyroid gland. Left untreated, hypothyroidism increases the risk of miscarriage and premature delivery.
8. Iodine Deficiency
The trace mineral iodine, found primarily in seafood, seaweed, plants that are grown in iodine-rich soil and iodized salt, is essential for the production of thyroid hormones. Conversely, taking in too much iodine can cause hypothyroidism. Iodine is an element that is needed for the production of thyroid hormone. The body does not make iodine, so it is an essential part of your diet.
Iodine is found in various foods. If you do not have enough iodine in your body, you cannot make enough thyroid hormone. Thus, iodine deficiency can lead to enlargement of the thyroid, hypothyroidism and to mental retardation in infants and children whose mothers were iodine deficient during pregnancy.