Thyroid nodule 4a is a description of color ultrasound classification, belonging to a kind of medium-high risk factors, may be malignant thyroid nodules, suggesting that there is a 20%~30% possibility of malignant changes. Clinically, thyroid nodules are generally divided into 6 levels according to the international classification, the higher the level, the greater the degree of malignancy in relative terms, level 4 is clinically divided into 4a, 4b, 4c, 4a level malignant possibility of about 20% ~ 30%, so in the clinical found 4a level of tumor history need to be dealt with. If the diameter of thyroid nodule is greater than or equal to one centimeter, fine needle aspiration of thyroid gland can be considered to determine the benign or malignant degree of thyroid grade 4a. If the diameter of thyroid nodule is smaller and it is not easy to puncture, ultrasound can be performed for review, and if the volume of the review is significantly larger than 50% than the last time, then surgery is needed for treatment. If you find thyroid 4a nodules in the clinic, it is recommended to consult the thyroid surgery department of regular hospitals, so as not to neglect your condition.