Polycystic kidney is a kidney parenchyma with numerous cysts of different sizes, the larger ones can be very large, the smaller ones can only be visible to the naked eye, making the whole kidney volume increase, the surface is uneven cystic protrusion, the cyst is yellowish plasma, sometimes dark brown or red-brown due to bleeding. The fluid contains urea, uric acid, creatinine, protein, phosphate and exfoliated epithelial cells. It is not an uncommon disease, but usually develops on both sides, and unilateral onset is extremely rare. The incidence is equal in both sexes. It can develop at any age, but most are found between 40 and 60. The disease has a family tendency to run in families, but it is uncommon to have congenital malformations of other organs in combination. Polycystic kidney is a congenital abnormal developmental disease, divided into two types: adult and infantile. The pathological change is the occurrence of numerous retained cysts in the renal parenchyma. The size of the cysts varies from several centimeters in diameter in large ones to sesame or green bean size in small ones or even smaller ones that are densely packed throughout the kidney. Ninety percent of polycystic kidneys are bilateral. Ultrasound performance of adult type polycystic kidney sonogram: the kidney volume is obviously enlarged, typically with abnormal morphology, and the surface is extremely irregular and often lobulated. There are numerous cysts of different sizes in the kidney with neat cavities, and the echogenicity of the renal parenchyma outside the cysts is more enhanced than normal. The echogenicity of the renal sinus region is often distorted by the majority of cyst-like echogenicity. In infantile polycystic kidney, the cysts are smaller in size and often do not show tiny cysts, or individual 1-2 cm cysts can be seen, with predominantly enhanced echogenicity of renal parenchyma and indistinguishable cortical and sinus areas. Differentiation between polycystic kidney and multiple renal cysts 1. The former is numerous cysts of different sizes, while the latter is only a few to a dozen cysts. The key points of differentiation between the two are 2. polycystic kidney has no intact renal parenchyma, and in the renal parenchyma without large cysts, the echogenicity is also obviously enhanced and higher than the internal echogenicity of normal liver or spleen; 3. renal parenchymal echogenicity of polycystic kidney cysts is still normal, and its echogenicity is lower than the internal echogenicity of liver or spleen. 4. polycystic kidney is mostly bilateral with liver cysts, along with renal insufficiency and family history 5. multiple renal cysts, unilateral is more common, and renal function is usually normal. There is no family history of the disease. 6.Generally the diameter of cyst is less than 4cm, no obvious compression of renal pelvis and calyces, no infection, malignancy, hypertension, or no obvious symptoms, only close follow-up observation and regular B ultrasound review are needed. Polycystic kidney treatment measures In the past, no active treatment measures were used for this disease, only supportive treatment including low salt and low protein diet, avoiding excessive strenuous activities, avoiding any infection and trauma, although the above measures are beneficial to protect the kidney function, but ultimately less positive significance. In recent years, in early diagnosed cases, when there are obstruction, stone, infection, and severe extrusion symptoms, medication, anti-infection, and surgical procedures must be considered, such as removing obstruction, removing stone, draining infection, and decompression surgery for oversized cysts. The prognosis of this disease is not good. In the past, the average survival time after the discovery of this disease in adult cases is generally 10 years on the right, while the survival time after the appearance of uremia is often not more than 5 years. Nowadays, for early cases, Chinese and Western medicines are actively used to treat the disease, and for advanced cases, dialysis treatment or kidney transplantation is used, so the prognosis is much improved compared with the past.