Metastasis of papillary thyroid cancer is usually mainly lymphatic metastasis in the neck, and lung and bone metastasis are rarely seen. Generally speaking, metastases in the lymph nodes of the neck have no obvious symptoms, and if the lymph nodes are superficial, an enlarged mass may be felt under the skin. Pulmonary metastases are usually asymptomatic and are usually detected by CT or ECT scans. In addition, metastases in bones are often accompanied by pain in bones. If the metastasis of papillary thyroid cancer is unilateral lymphatic metastasis, it will usually cause compression of blood vessels, resulting in difficulty in blood supply to the body, which often shows symptoms such as weakness, lack of oxygen, pallor and muscle weakness.