The most common cause of hyperthyroidism is Graves' disease, an autoimmune disorder. However, toxicological factors can also play a role. Exposure to certain chemicals and environmental toxins can disrupt thyroid function. For instance, excessive iodine intake, often from supplements or medications, can lead to an overactive thyroid. Additionally, polychlorinated biphenyls (PCBs) and perchlorates, found in contaminated water or soil, have been implicated in thyroid dysfunction.
