Taking anti thyroid medicines or surgically removing the thyroid gland are some of the reasons behind underactive thyroid
The thyroid gland is a butterfly shaped gland found in the neck area that performs the function of producing two hormones commonly referred as T3 and T4. The most important task that these hormones do is to maintain normal metabolic rate. Apart from regulating metabolism, a number of biological processes in our body depend on the production of thyroid hormone. When the thyroid gland is incapable of manufacturing hormones in sufficient amounts, the condition is referred as underactive thyroid (hypothyroidism). Excessive tiredness, dry skin and constipation are some of the underactive thyroid symptoms in women.
Causes
Treatment options for hyperthyroidism (overactive thyroid gland) that include medicines and surgery can damage the thyroid gland leading to hypothyroidism. It is discussed below:
Medications
People suffering from hyperthyroidism or overactive thyroid (a condition in which the thyroid gland develops an unusual ability to produce more than normal amounts of hormone) are advised to take anti-thyroid medicines. These medications are formulated to decrease the size of the thyroid gland. With the reduction in the size of the thyroid, production of hormone also decreases. Prolong or too much use of these medications can disable the thyroid gland permanently, leading to reduced production of the hormone.
Surgery
In case medications do not help to cure hyperthyroidism, the doctor may recommend surgery in which a major part of the thyroid gland is removed. However, this hyperthyroidism treatment increases the risk of underactive thyroid gland. This is because only a small portion of the thyroid gland is left after surgery, which may not be enough to produce hormones in adequate amounts. Also, if the surgery involves removal of the entire thyroid gland, the source of the hormone in the body is lost permanently. As a result, women who underwent surgery to treat hyperthyroidism may eventually get diagnosed with underactive thyroid that may last for a lifetime.
Hashimoto’s Thyroiditis
In this condition, the thyroid gland is subjected to destruction, which is carried by antibodies produced by the immune system. In other words, the immune system orders its antibodies to attack the tissues of the thyroid, resulting in poor functioning of the butterfly shaped gland. Doctors are yet to identify the reason behind this unusual behavior of the immune system that leads to underactive thyroid. People diagnosed with type 1 diabetes tend to suffer from Hashimoto’s thyroiditis.
Dysfunction of the Pituitary Gland
When the pituitary gland that is assigned the task to regulate thyroid function, does not work properly, one may suffer from underactive thyroid gland. The pituitary gland found in the brain is also referred to as the master gland as it manages the functions of various glands. For the thyroid gland to produce hormones, it needs to be stimulated. This is done by the pituitary gland that makes a hormone known as thyroid stimulating hormone (TSH). So, when the thyroid gland comes in contact with TSH, the butterfly shaped gland releases hormones T3 and T4 into the bloodstream. However, when the pituitary gland is not functioning correctly, production of TSH hormone may reduce drastically. This in turn may have a negative impact on the thyroid gland. To be more specific, deficiency of TSH hormone may lead to underactive thyroid. Formation of pituitary tumors is one of the causes of dysfunction of this master gland.
Radiation Therapy
This form of treatment is commonly used to treat cancer patients. The cancer site is bombarded with high energy rays (gamma rays) to destroy the cancerous cells. However, if the targeted area is somewhere around the neck, it can damage the thyroid gland, which may also cause hypothyroidism.
Pregnancy
Pregnancy is yet another factor responsible for causing underactive thyroid in women. Hormonal imbalance at the time of pregnancy may interfere with thyroid gland function. Yet another reason is the increased demand of thyroid hormone due to the developing baby in the womb. The thyroid gland may not be able to fulfill this new requirement of thyroid hormone leading to hypothyroidism. One study showed that 0.2% women during pregnancy get diagnosed with underactive thyroid gland. Hypothyroidism may also occur anytime within a span 12 months after pregnancy.
Iodine Deficiency
Iodine deficiency, rarely diagnosed in United States, can also trigger underactive thyroid in women. The thyroid gland finds it extremely difficult to manufacture hormone when iodine is not present adequately in the blood. In other words, hormone production of thyroid gland relies on sufficient iodine levels. Inadequate iodine in the diet is likely to cause hypothyroidism.
After diagnosing the underlying causes, underactive thyroid treatment is given accordingly. Orally taking drugs like levothyroxine that have synthetically prepared hormone in them is usually the first line of treatment of hypothyroidism. Patients suffering from iodine deficiency may be advised to follow a underactive thyroid diet, which works to resolve the issue.
