The biggest characteristic of undifferentiated thyroid cancer is its high malignant degree, rapid growth, development and spread, and poor prognosis. It is recommended that patients go to the hospital in time for examination, early detection, early diagnosis and early treatment, so as to avoid spreading or metastasis of the cancer cells, and timely treatment can effectively prolong the survival time of patients. Undifferentiated thyroid cancer is a pathological type of thyroid cancer, which belongs to the one with higher degree of malignancy. It is characterized by a high degree of malignancy, rapid growth, rapid enlargement of cancer cells within two months, and early infiltration and metastasis, such as in the lungs and skeletal tissues. Undifferentiated thyroid cancer may be accompanied by symptoms such as difficulty in aspiration, difficulty in swallowing, hoarseness, and jugular vein varicose. Its treatment is less effective and the average survival time is shorter. In addition, patients are advised to go to the hospital in time. Early undifferentiated thyroid cancer, whose tumor has not spread and metastasized, can be treated with radical surgical resection or radiotherapy and chemotherapy to improve the survival rate of patients. Diet should avoid spicy, greasy and other stimulating foods.