24.07.2021 – 07:42
Hypothyroidism can develop for a number of different reasons, the most common being an autoimmune attack on the thyroid gland, called Hashimoto’s thyroiditis. Hypothyroidism (low thyroid activity) can also be the result of taking a medicine like lithium, genetic, or an underlying pituitary gland problem.
Understanding the “why” behind a diagnosis of hypothyroidism is essential to moving forward with a proper treatment plan. While some people may require lifelong thyroid hormone replacement, others may have a short-lived case of hypothyroidism (for example, postpartum thyroiditis), and should stop taking a medication or seek further diagnostic tests such as imaging. pituitary gland.
Hashimoto’s thyroiditis is more common in women, and while it can occur at any age, it is more common as men get older. For women, Hashimoto often develops during pregnancy, after childbirth or around the time of menopause.
Other causes of hypothyroidism include:
* Surgery
People with hyperthyroidism, thyroid nodules or thyroid cancer may need surgery. If the entire thyroid gland is surgically removed, a person will be hypothyroid and seek medication to replace thyroid hormones throughout life. If only part of the thyroid gland is removed, there is a good chance that it will again be able to make enough thyroid hormone.
* Radiation
Instead of thyroid surgery or antithyroid drugs, some people with hyperthyroidism are treated with radioactive iodine, which will destroy the thyroid gland, making a person hypothyroid. People undergoing radiation treatment for Hodgkin’s lymphoma or head and neck cancer are also at risk of developing hypothyroidism.
* Thyroiditis
Thyroiditis describes inflammation of the thyroid gland and is a general term for a variety of thyroid conditions.
Another example of thyroiditis is subacute thyroiditis (also called de Quervain thyroiditis), which is believed to be caused by a virus. With this type of thyroiditis, a person experiences hyperthyroidism (high thyroid activity) followed by hypothyroidism, in addition to a soft thyroid gland.
*Medicines
Some medications can cause hypothyroidism. These medications include:
lithium
Amiodarone
Thionamide (antithyroid drug)
Alfa-interferon
Interleukin-2
Certain cancer medicines (tyrosine kinase inhibitors and checkpoint inhibitory immunotherapies)
* Excess or lack of iodine
Too much iodine (for example, from dietary supplements) can cause or worsen hypothyroidism. In addition, an iodine deficiency can cause hypothyroidism. Iodine is needed for the production of thyroid hormone and is found in foods such as dairy products, chicken, beef, pork, fish, and iodized salt.
* Congenital hypothyroidism
Some babies are born without a thyroid gland or with only a partial thyroid gland. Since there is not a thyroid gland (or not enough) to produce thyroid hormone, hypothyroidism develops, which is serious and requires treatment with a thyroid hormone pill.
* The problem of the pituitary gland
The pituitary gland is located in the brain and stimulates other glands inside the body, such as the thyroid gland, to release hormones. If the pituitary gland is damaged by a brain tumor, radiation or brain surgery, it may not function well enough to signal the thyroid gland. This can then result in it becoming inactive. This type of hypothyroidism is called central or secondary hypothyroidism.
* Infiltrative diseases
Rarely, certain diseases, such as hemochromatosis, may deposit abnormal substances (iron, in the case of hemochromatosis) in the pituitary gland, causing central hypothyroidism, or less frequently in the thyroid gland, causing primary hypothyroidism.
* Genetics
DNA plays a role when it comes to developing autoimmune hypothyroidism, and this has been supported by a number of studies.
When looking at specific genes linked to Hashimoto, scientists have found mutations in genes for human leukocyte antigen (HLA), T cell receptors, and other molecules involved in the immune system.
To further support the role of genes in the development of Hashimoto’s thyroiditis, people with Turner syndrome and Down syndrome (both of which are of genetic origin) have a higher-than-expected rate of autoimmune thyroid disease, particularly Hashimoto’s thyroiditis.
However, it is important to remember that genes are just one factor that helps you predict the risk of developing hypothyroidism. There are many other factors that come into play, such as pregnancy or taking certain medications.
In the end, it is the combination of genes and an environmental cause that predict a person’s unique risk of developing hypothyroidism.
