Hypothyroidism is a condition with an under-performing thyroid. There are many different causes of hypothyroidism where some are more prevalent than others. However, an autoimmune disease is considered the primary cause of the condition as it accounts for about 90% of adult cases with a majority associated with Hashimoto’s disease.
What is an autoimmune disease?
This is a disease that confuses the immune system such that instead of immune cells attacking the bacteria and viruses attacking the body, they attack the normal healthy tissues instead of protecting them. This is what happens to the thyroid gland by the immune cells. Once the thyroid gland is attacked, production of thyroid hormones is inhibited hence no more cells are left to produce enough hormones as required in the body. It has been established that the condition is more common in women compared to men and tends to become more prevalent with age.
This is the most common autoimmune disease that causes shrinking of the thyroid. The condition may also cause Hashimoto’s thyroiditis which is the inflammation of the thyroid gland. Besides Hashimoto’s disease, thyroiditis may also be caused by viral infections. In such cases of viral infections, the thyroid gland is forced to release all the stored thyroid hormone into the bloodstream making the thyroid to be overactive for a short while then becoming underactive after all the thyroid hormones have been released.
Luckily, viral thyroiditis can be treated effectively with more than two-thirds of the patients likely to regain their thyroid function. However, the other one third may be left with permanent hypothyroidism.
Other causes of hypothyroidism
We mentioned earlier that besides autoimmune disease, hypothyroidism has many different causes. However, these causes are considered less prevalent compared to the autoimmune disorders. Some of them include;
- Surgical removal of the thyroid in part or as a whole especially for patients with thyroid cancer, Grave’s disease and thyroid nodules- The aftermath of such surgeries is a failure of the remaining thyroid to work properly.
- Radioactive therapies- radiative iodine therapy is a common treatment option for thyroid cancer and nodular goiter among other conditions. The radioactive iodine may destroy the thyroid tissue to cause hypothyroidism.
- Congenital problems- in this case, it means one was never born with the thyroid gland or had a malformed one. This is rare but is still possible. In some other instances, some babies are born with a thyroid gland in the wrong place (ectopic thyroid). This case, for example, may cause thyroid cells as well as enzymes to malfunction. Research indicates that the occurrence of this is in the ratio of 1:3000 births.
- Other causes may be related to Iodine levels. In case of iodine imbalance, hypothyroidism may get worse.
- Dysfunction of the pituitary gland- the pituitary gland plays a critical role in the production of the thyroid hormones. The pituitary gland produces the thyroid-stimulating-hormone which defines how much of the thyroid hormone should be produced. That is why in cases of injuries, tumors, surgeries or radiations that affect the pituitary gland, THS will not be, and that will result in inadequate production of thyroid hormones.
Hypothyroidism is by a large extent an autoimmune disease. However, different other factors may cause the condition. If left untreated, it may result in many health complications including goiter, mental health problems, cardiovascular conditions, congenital disabilities, and Myxedema which is a severe condition of hypothyroidism and is life-threatening.