Retest means to review. In some diseases, when the doctor gives the diagnosis and treatment, he will tell the patient how often to go back to the hospital for examination. The purpose is to observe the effect of treatment and whether there is any recurrence after treatment. Benign nodules are commonly used in the follow-up treatment, such as thyroid nodules or breast nodules, breast hyperplasia and other breast diseases, sometimes the breast can appear lump-like changes, usually applying the treatment of proprietary Chinese medicine can be. Of course, doctors will also tell patients that they need to go to the hospital for ultrasound examination in 3-6 months to know the changes of their nodules. The most common type of thyroid nodule is nodular goiter. Nodules smaller than 3cm can be treated conservatively but should be examined regularly in the hospital. If the nodule is significantly larger or if the nodule has compressive symptoms, surgery is needed.