Left renal cyst is very common in clinic. Renal cyst is a benign disease and usually does not cause serious consequences. Whether renal cyst has symptoms generally depends on the size of the cyst. Generally speaking, smaller renal cysts will not cause clinical symptoms and will not affect human health. For huge renal cysts, it often causes compression symptoms and makes the patient's waist feel sore. If renal cyst causes urinary tract obstruction, it will cause hydronephrosis and other symptoms. Renal cyst is huge, which may compress the renal parenchyma and gradually shrink the renal parenchyma, thus affecting renal function. Therefore, giant renal cysts can generally be treated by surgery in clinic. The main surgical method is laparoscopic unroofing and decompression of renal cyst. The recurrence of cyst can be effectively prevented by sucking the cyst fluid and removing the cyst wall. Generally speaking, renal cyst is a benign lesion, and early diagnosis and treatment will generally not have a great impact on the human body.