The first thing to know about left kidney cyst is the size of the cyst, usually the diameter of the cyst alone does not exceed 5cm, and in most cases there are no symptoms. In case of combined symptoms, it is usually necessary to consider the traumatic condition and whether there is infection, if it is infected, symptoms such as pain or hematuria will appear. If the kidney cyst is >5cm in diameter, it may compress the kidney peritoneum or compress the surrounding tissues, and then it may show soreness in the left lumbar region, or sometimes it may affect bowel movement and show abdominal distension. Therefore, the left kidney cyst must be checked for the size of the cyst and attention should be paid to whether there is usually hematuria or trauma.