How long a patient with grade IV thyroid can live needs to be analyzed on a case-by-case basis. It is mainly related to the benign or malignant nature of the nodule, if it is benign, it does not affect the life expectancy; if it is malignant, it is also related to the age, pathology, size of the tumor, and the presence or absence of lymph nodes or distant metastasis. According to the size and shape of thyroid nodules under color ultrasound, thyroid nodules are classified into 6 grades, the higher the grade, the higher the degree of malignancy, thyroid nodule grade 4 represents that the patient’s nodules have a probability of 2%-90% to be malignant nodules. However, the benign or malignant nature of the tumor needs further puncture biopsy to be clarified. If the nodule is benign, it does not affect the life expectancy; if it is malignant, it is also related to the pathology, the size of the tumor, the presence of lymph nodes or distant metastasis. The pathology of thyroid malignant tumors is divided into 4 categories (papillary carcinoma, follicular carcinoma, undifferentiated carcinoma, medullary carcinoma), of which papillary carcinoma has a better prognosis, follicular carcinoma has a worse prognosis than papillary carcinoma, undifferentiated carcinoma has a very poor prognosis, and medullary carcinoma is moderate. In addition, the prognosis of patients with thyroid malignant tumors who are older than 45 years old, with tumor diameter >1cm, with lymph node metastasis or distant metastasis is not as good as that of patients who are younger than 45 years old, with tumor ≤1cm and without metastasis. The exact time still depends on the patient’s condition. If patients find grade IV thyroid nodules, it is recommended to seek medical attention as soon as possible to clarify the nature so as not to delay the condition.