Thyroid nodules of 4mm with unclear borders are usually treated with follow-up observation, medication or surgery according to the nature of the nodule and the patient’s thyroid function. 1. If the nodule is benign and the patient’s thyroid function is normal, regular ultrasound examinations of the thyroid gland can be performed to monitor changes in the nodule, and no treatment is needed for the time being. 2. If the nodule is benign, but the thyroid function is hypothyroid or hyperthyroid, then choose thyroxine tablets, formamidazole and other drugs to treat. 3. If the nodule is malignant, it is generally recommended to do radical surgery to remove the malignant tumor as soon as possible, and some patients also need to do iodine 131 treatment and take thyroxine tablets after the surgery. It is recommended that the patient further improve the relevant examination to clarify the nature of the nodule in the doctor’s guidance to choose the appropriate treatment, so as not to delay the condition.