a nurse feeling a patient's throat for a swollen thyroid

Hypothyroidism Causes

Hypothyroidism is a condition characterized by an underactive thyroid that does not create enough hormones to maintain the delicate balance for bodily functions to operate correctly. This glad, which is located at the front of the neck, right at its base, produces the main types of hormones that will regulate a person's metabolism and ensure that the body will metabolize carbohydrates and other fats for energy correctly. There are many different reasons why this system can be thrown out of balance.

Iodine Deficiency

The most common contribution to hypothyroidism is a deficiency of the mineral iodine. Iodine helps to regulate thyroid function and growth. Since seafood is common food source of iodine, deficiency often occurs in areas that are far inland or in mountains regions with iodine-poor soil. Iodine deficiency as a cause is largely tied to developing nations and areas where iodized salt is uncommon.

Autoimmune Diseases

The second most common cause of hypothyroidism is Hashimoto's thyroiditis, which is an autoimmune disorder in which the body's immune system invades or attacks the thyroid. Patients' thyroids will become damaged over time with this autoimmune disorder until they are eventually unable to produce hormones necessary for important bodily functions.

Treatment for Hyperthyroidism

Hyperthyroidism is an opposite condition. It is characterized by the production of too many hormones by the thyroid rather than too few. This, also, can cause the delicate hormonal balance of the body to be thrown off kilter, similar to hypothyroidism. In order to treat this case, types of radioactive iodine may be used. However, if the treatment continues for an extended period of time, there is a chance that hypothyroidism will be triggered and will become a chronic problem.


Some different medications can either cause hypothyroidism or increase its severity. One such medication is lithium, which is used in several different psychiatric medications that are used to regulate disorders such as bipolar disorder and schizophrenia. To prevent these medications from causing serious harm, it is recommended to constantly monitor the thyroid and metabolism so that any problems can be identified and resolved early.

Thyroid Surgery

Occasionally, a large part of the thyroid will need to be removed through a surgical process because it has become diseased or cancerous. Removing part of the thyroid might be necessary to increase a person's overall health, but by removing a large section, the thyroid might cease to function as well as it once did, or at all. If this occurs, patients will need to take medication that will boost the amount of thyroid hormones that are being produced for the rest of their life.

Congenital Disease

Occasionally, infants are born with thyroid glands that are not functioning, underdeveloped, or simply absent. There is no concrete consensus as to why this occurs. Many hospitals are now required to test all newborns for thyroid function.


Another less common cause of hypothyroidism is pregnancy. A woman's body undergoes a multitude of changes while she is pregnant, and these changes can result in imbalance or complication of proper hormone function.

Last Updated: March 09, 2016