The difference between multiple renal cysts and polycystic kidneys is mainly the definition of the disease and the cause of the disease, etc. Both of them have similarities in clinical symptoms and treatment modalities. Multiple renal cysts usually refer to multiple simple renal cysts, which are common lesions of kidney diseases, while polycystic kidney is a congenital hereditary disease. The etiology of polycystic renal cysts is not clear. Renal cysts originating from the renal tubules are mostly thought to be associated with obstruction of the renal units, and those of non-tubular origin are mostly thought to be formed by proliferation of epithelial cells. Polycystic kidneys are mainly caused by genetic mutations and can also be caused by long-term dialysis treatment. Both diseases can compress the renal parenchyma or pull the renal peritoneum, resulting in distension and pain in the renal region, and symptoms such as fever, hematuria, and pyuria can occur when secondary infection or combined with urinary tract obstruction occurs. If symptoms and complications occur both diseases are mainly treated by surgery. If patients have multiple renal cysts or polycystic kidneys, it is recommended to go to regular hospitals in time and standardize the treatment under the guidance of doctors.