In front of the mirror, lightly press both sides of the trachea in front of the neck with your fingers and gently touch with your fingertips. First, pay attention to the size and shape of the goiter, and compare both sides to see if there is a lump; second, if a lump is found, pay attention to the size of the lump. Generally, the diameter of a single nodule of benign tumor or cyst is mostly around 2 cm; when the diameter exceeds 2 cm, thyroid cancer should be suspected; third, pay attention to the smoothness and softness of the lump. A single lump with smooth and uniform surface may be adenoma; a single one, which does not behave smoothly and has a solid feeling, should be suspected as cancer; fourthly, the growth rate of the lump should be noted. For benign tumors and cysts, the course of the disease can be months to years without significant changes; for thyroid cancer, the growth of the lump is obvious; fifthly, attention should be paid to whether lymph nodes can be palpated around the lump in the neck. If hard lymph nodes can be touched in the neck around the thyroid gland, prompt medical attention should be sought.