The thyroid gland is divided into 6 levels, which are mainly used to diagnose benign and malignant. Each level represents a different reference index: 1. Thyroid level 1, ultrasound shows a normal sized thyroid gland with no nodules or cysts. 2. Thyroid level 2 is a benign nodule with clear margins and calcification or coarse calcification. 3. Thyroid level 3 is a benign nodule with a small chance of a malignant nodular mass. 4. Thyroid level 4, possible There is a malignant lesion with incomplete margins and the incidence of malignancy is 5%-85%. 5.Thyroid grade 5, ultrasound suggests that the nodule is malignant with a high possibility of malignancy. 6.Thyroid grade 6, pathologically detected as thyroid nodule cancer.