Calcification of the left lobe of the thyroid gland is considered to be caused by benign thyroid nodules, thyroid cancer and other diseases, with different treatments for different diseases. 1. Benign thyroid nodules: If the patient has no obvious symptoms, no special treatment is needed, and regular review is enough. If the enlarged thyroid gland compresses the trachea, surgery is needed to remove it. 2. Thyroid cancer: Thyroid cancer can also appear as calcification of the left lobe of the thyroid gland, and there will be lumps or nodules in the patient’s neck, and due to the pressure of the tumor, there will be dyspnea and other phenomena, and the patient can follow the doctor’s instruction to undergo thyroidectomy and cervical lymph node dissection. In addition, some patients need postoperative radiotherapy. In addition, there are many other causes of left-sided thyroid with calcification, and it is recommended that patients go to the hospital in a timely manner to clarify the cause of the disease and receive treatment as soon as possible.