It is not possible to simply compare the severity of hydronephrosis and renal cyst, which can be judged according to the cause of the disease and the symptoms and manifestations.
When urine drainage from the renal pelvis is blocked, the pressure inside the kidney increases after accumulation, the renal pelvis and calyces dilate, the renal parenchyma atrophies, and the function decreases, which is called hydronephrosis. Causes of hydronephrosis include stones, tumors, etc. Tumors are more serious. If the hydronephrosis affects the renal function, hyponephrosis, oliguria, etc., it is more serious.
Renal cysts are divided into simple renal cysts and polycystic kidneys and so on. Simple renal cysts are small, asymptomatic and usually not serious; larger cysts and decreased renal function are more serious. Polycystic kidney is a hereditary disease, which is more serious and needs to be treated as early as possible.
Patients with hydronephrosis and renal cysts should go to the hospital in time and be treated under the guidance of professional physicians.