Thyroid 4a with unclear boundary needs further examination to confirm the diagnosis. If the thyroid gland is malignant nodule, it should be treated by surgery under the guidance of doctor in time. In the color ultrasound examination of the thyroid gland, thyroid nodules are divided into 6 grades, the higher the grade, the higher the risk of thyroid cancer. Thyroid nodules graded at grade 3 or below have a higher probability of being benign, grade 4 or above may be malignant, and grade 6 can be determined to be malignant. A 4a is a low suspicion of malignancy, with a malignancy rate of 2% to 10%. If there are signs of malignancy during the examination, at this time the patient can be further examined by nodule puncture pathology, if the diagnosis of malignant lesions, according to their own situation, under the advice of the doctor in a timely manner through surgical resection treatment. Patients should pay attention to a balanced and nutritious diet, and follow the doctor’s instructions to do regular reviews to avoid further deterioration of the condition.