Thyroid hypoechoic 3mmx2mm generally refers to a thyroid size of 3mmx2mm hypoechoic nodule. Hypoechoic is a description of the lesion by thyroid ultrasound, and different tissues have different echo signals, which can be classified as strong echo, high echo, isoechoic, low echo, weak echo, and no echo. The nature of thyroid nodules cannot be judged by hypoechoicity alone, but should be combined with other descriptions of the nodule. For example, irregular edges of the nodule, imbalance of the aspect ratio, and tiny calcifications, etc., are mostly suggestive of malignant risk and require fine needle aspiration biopsy of the thyroid gland; if the edges are regular, and the calcifications are coarse, etc., they are mostly suggestive of benign nodules. Hypoechoic thyroid nodules are recommended to be treated under doctor’s supervision.