Thyroid nodule 5cm is considered as several grades need to be evaluated to determine whether the boundary of the nodule is clear, whether the internal echoes are regular, whether there is mud calcification, etc. It cannot be determined solely on the basis of the size, and it is recommended to consult a doctor in a timely manner. In the color ultrasound examination of the thyroid gland, the size, shape, blood flow and other aspects of the thyroid nodules are evaluated comprehensively, and the thyroid nodules are divided into 6 grades, and the higher the grade, the higher the risk of thyroid cancer. Thyroid nodules with a grade of 3 or below have a higher probability of being benign nodules, while those with a grade of 4 or above may be malignant, and a grade of 6 can be determined to be malignant. Thyroid nodules of 5 centimeters are relatively large nodules, first of all, determine whether the patient has symptoms of pressure, whether to show breathing difficulties or hoarseness and other clinical symptoms of pressure, found that this situation needs to be actively given surgical treatment. Therefore, you can not judge the benign or malignant degree of thyroid nodules purely from the size, but should combine the above to determine whether there are signs of malignant changes in thyroid nodules, and if necessary, carry out fine needle aspiration of thyroid nodules, and consult the thyroid surgery department of regular hospitals in a timely manner.