Autoimmune-induced damage to the thyroid gland is the cause of Hashimoto’s disease. Although thyroid gland injury is the cause of hypothyroidism, patients will continue to experience characteristic symptoms as a result of the underlying autoimmunity.[1] With autoimmune diseases, the body inappropriately interprets self-tissues as harmful pathogens, generating antibodies that cause the immune system to target parts of the body, such as the thyroid gland in Hashimoto’s disease. As with most autoimmune diseases, the mechanisms responsible for the breaking of self-tolerance are not well understood and likely involve a combination of environmental factors and genetics.
The link between Hashimoto’s disease and genetics is relatively strong, with studies in monozygotic twins suggesting that an estimated 79% of Hashimoto’s disease risk may be driven by genetic factors.[2][3]
Although well-tolerated in healthy individuals, high dietary iodine intake can cause hypothyroid symptoms in people with Hashimoto’s disease by suppressing thyroid hormone production.[4]