Thyroid nodule 4A is a kind of grading under ultrasound of the thyroid gland, which is a low-grade suspicious malignant nodule with a malignancy rate of 2% to 10%. According to the TIRADS classification criteria, thyroid nodules are graded, usually into 1~6 grades, the higher the grade, the higher the risk of thyroid cancer, grade 4 suggests suspected malignancy, and grade 4 is divided into 3 categories, 4A, 4B and 4C, and 4A is a low-grade suspected malignancy, with a malignant incidence rate of 2%~10%. Thyroid nodule refers to a limited mass due to abnormal proliferation of thyroid cells. If the ultrasound result shows a 4A thyroid nodule, further investigations, such as a puncture biopsy of the thyroid nodule, are usually recommended. Based on the pathological results, the nature of the nodule will be determined to be benign or malignant, and will provide a basis for the next step in the treatment approach. If the test result shows that the thyroid nodule is 4A, the patient should actively cooperate with the doctor to further improve the relevant examination, to clearly diagnose the nature of the nodule, and carry out treatment under the doctor’s guidance.