4b thyroid nodule is relatively serious, but not absolutely, need to be further combined with pathological examination. According to the TI-RADS classification, thyroid nodule 4b indicates that the nodule has the possibility of malignancy, and the probability is about 10% to 50%. Thyroid nodule 4b can only indicate that there is a risk of malignancy, and can not directly determine its severity, but also need to be combined with pathological examination. Thyroid nodules category 4b need further fine needle aspiration biopsy to clarify the benign and malignant nature of the thyroid nodules, if malignant, need surgical treatment, but thyroid nodules category 4b even if malignant, if found early, its prognosis is generally better. Thyroid nodules category 4b need to promptly go to the hospital, further improve the examination, under the guidance of the doctor’s treatment.