Whether a solid thyroid nodule class 4A is serious or not needs to be determined according to the pathological results. If the pathological results are benign, it means it is not serious, while if the pathological results are malignant, it means it is serious. 1. Not serious: If the thyroid ultrasound classification suggests a solid thyroid nodule class 4A nodule, also known as a low-grade suspicious malignant nodule, the possibility of malignancy is 5%-10%, further ultrasound-guided Further ultrasound-guided puncture, or direct surgery to remove the lesion for pathological examination is required to clarify the diagnosis. If the pathology result is benign, it means the situation is not serious. You can follow the doctor’s instruction to review the thyroid ultrasound examination every 3 months to monitor the changes of solid thyroid nodules. Radical thyroid cancer resection should be performed. After surgery, oral medications such as levothyroxine sodium tablets are needed to help replenish thyroid hormones, and thyroid function should be reviewed regularly to help adjust the medication dosage. Patients with solid thyroid nodules 4A are advised to go to a regular hospital for the next step of treatment and to take care of their rest and avoid staying up late, strenuous exercise and overwork.