Renal cysts 0.3~0.4 cm are usually not serious and generally do not require treatment. Renal cysts 0.3 ~ 0.4 cm, usually have no clinical symptoms, do not need special treatment, but need to be regularly reviewed, usually not serious, but if there is a combination of infection or the increasing size, then need to be treated. If the renal cyst is combined with infection, anti-infection treatment should be carried out, as well as the treatment of renal cyst puncture drainage. If the size of renal cyst is too large with a diameter of more than 4cm or symptoms related to compression of the surrounding tissues, the cyst should be punctured and drained in time and treated with intracapsular injection of sclerosing agent; cystectomy or even nephrectomy should be considered for patients with a huge cyst with a volume of more than 500 ml, a tendency of malignant changes or recurrence after puncture. If you suffer from renal cysts, you can seek medical treatment in regular hospitals and choose the appropriate treatment under the advice of doctors.