Benign and malignant thyroid tumors should be distinguished from the following aspects: 1. In terms of symptoms and signs: benign thyroid tumors are asymptomatic, the lumps are oval or round and vary in size, the lumps move well without adhesions with the surrounding area and move up and down with swallowing, the surface of the lumps are smooth and the borders are clear. In contrast, malignant thyroid tumors often have discomfort such as swelling and urgency in the neck, the tumor is generally hard, irregular, with clear borders and poor activity, some patients have enlarged lymph nodes in the neck, individual patients also have facial flushing and diarrhea, etc. 2. If a cold nodule is present, it is likely that a needle aspiration smear cytology will be needed to perform a pathological examination. If the needle smear cytology is benign, there is also a 10% chance of malignancy, and surgical excision is possible.