Renal cysts are a general term for the presence of cystic masses of varying sizes in the kidney that do not communicate with the outside world. Common renal cysts can be classified as adult-type polycystic kidney, simple renal cysts and acquired renal cysts. The vast majority of renal cysts are asymptomatic. Physical examination is mostly normal, and occasionally a mass can be palpated or percussed in the kidney area. If the cyst becomes infected, there may be pressure pain in the abdomen. Some patients may have the following symptoms due to the cyst itself and the increased pressure inside the cyst, infection, etc.: 1. Discomfort or pain in the lower back and abdomen: The cause is due to the enlargement and expansion of the kidney, which increases the tension of the kidney envelope and strains the kidney tip, or causes pressure on the neighboring organs. In addition, polycystic kidneys cause the kidneys to contain a lot of water, become heavy, and drop and pull, which also cause pain in the lower back. The pain is characterized by vague and dull pain, fixed on one or both sides, radiating to the lower part and low back. If there is intracapsular hemorrhage or secondary infection, the pain will suddenly increase. If combined with stones or blood clots blocking the urinary tract after bleeding, renal colic may appear. 2.Hematuria: It can be manifested as microscopic hematuria or meatus hematuria. The attack is periodic. Back pain often increases during the attack, and can be triggered or aggravated by strenuous exercise, trauma and infection. The reason for bleeding is that there are many arteries underneath the wall of the capsule, and due to increased pressure or combined infection, the blood vessels of the capsule wall rupture and bleed due to excessive strain. 3, abdominal mass: Sometimes it is the main reason for patients to visit the clinic, and 60% to 80% of patients can palpate the enlarged kidney. Generally speaking, the larger the kidney, the worse the kidney function. 4.Proteinuria: Generally the amount is not much, not more than 2g in 24 hours. more will not occur nephrotic syndrome. 5.Hypertension: solid cyst presses the kidney, causing renal ischemia, which increases renin secretion and causes hypertension. In the normal kidney function, more than 50% of patients have hypertension, and the incidence of hypertension is higher when the kidney function is decreasing. 6.Decreased renal function: Due to the occupancy and compression of cyst, the normal kidney tissue is significantly reduced and the renal function is progressively decreased.