The cause of thyroid nodules is still unclear. It is considered that it may be related to family genetics, environmental factors, thyroid-related hormone disorders, abnormal iodine intake, inflammation and other factors. 1. Familial inheritance: If there are patients with thyroid nodules in the family, the incidence of thyroid nodules in their parents and offspring will be increased accordingly. 2. Environmental factors: People who are frequently exposed to ultraviolet rays or X-rays have a higher incidence of thyroid nodules. 3. Thyroid-related hormone disorders: If the levels of thyroid stimulating hormone, triiodothyronine, tetraiodothyronine and other hormones are abnormal, the likelihood of thyroid nodules increases. 4. Abnormal intake of iodine: Consuming too much iodized salt or too little iodized salt for a long period of time may lead to hyperplasia of thyroid cells and formation of thyroid nodules. 5. Inflammation: When the thyroid gland is stimulated by inflammation, such as acute suppurative thyroiditis and Hashimoto’s thyroiditis, the likelihood of thyroid nodules also increases. It is recommended that when thyroid nodules occur, you should go to the hospital in time for a scientific and complete examination to clarify the cause of the disease, and then follow the doctor’s instructions to carry out scientific and effective treatment.