Causes and Risk Factors for an Enlarged Thyroid

The causes and risk factors of an enlarged thyroid are relatively straightforward. Those living in Third World countries or areas where the soil lacks certain elements often suffer from this condition. In other cases, it's the effect of the body attacking itself.

Goiter

• An enlarged thyroid is commonly referred to as a goiter. The swelling of the thyroid is clearly visible on an ultrasound or X-ray and often may grow to an extent that it can be seen by the naked eye.

Types

• There are two types of goiter: endemic and sporadic. "A simple goiter can occur for no known reason, or when the thyroid gland is not able to produce enough thyroid hormone to meet the body's needs," according to the School of Medicine and Public Health at the University of Wisconsin. "The thyroid gland makes up for this by becoming larger."

Risk Factors

• Individuals prescribed lithium sometimes develop goiter. Females are most likely to have the condition. Other risk groups include those living in countries where iodized salt is not prevalent, individuals over the age of 40 and people with a family history of goiter.

Cause

• An iodine deficiency is the leading cause of goiter, explaining its presence in cultures where iodized salt isn't available. In industrialized nations, the enlarged thyroid is most commonly a result of an auto-immune disorder such as Hashimoto's disease.

Hashimoto's Disease

• According to the Mayo Clinic, Hashimoto's disease, also known as chronic lymphocytic thyroiditis, occurs as the immune system attacks the thyroid gland, damaging cells and enlarging the thyroid. The resulting inflammation often leads to an underactive thyroid gland (hypothyroidism).