Thyroid nodules are mainly caused by the following: First, thyroid inflammation, the thyroid gland is the main endocrine organ of the body, inflammation and degeneration of the thyroid gland can lead to nodules, thyroid nodules can occur on one side or both sides at the same time. Secondly, the body’s intake of the trace element iodine is too low, due to the low iodine content in the soil and water in some areas, resulting in low iodine intake, which leads to thyroid nodules. Third, some drugs can also cause thyroid nodules, such as sulfonamides and para-aminosalicylates, which can hinder the synthesis and release of thyroxine, leading to nodules in the thyroid gland or causing an enlarged thyroid gland. The development of thyroid nodules can cause hoarseness and other symptoms, so if thyroid nodules appear in your body, you should pay attention to them and go to the hospital in time.