The specific cause of renal tumor is not clear at present, it may be related to heredity, smoking, high blood pressure, obesity, etc. Early stage may not have obvious symptoms, with the progress of the disease may appear waist pain, hematuria and other related symptoms. Kidney tumor can be divided into benign and malignant tumors, the specific cause is not particularly clear, many factors are related, such as heredity, hypertension, obesity, smoking and so on. In the early stage of renal tumor, there may not be any symptom, with the progress of the disease, especially when the malignant tumor invades into the renal pelvis, hematuria, low back pain can occur, and when the tumor is relatively large, you can feel the mass in the abdomen. If there are waist pain, blood in urine, especially painless and intermittent hematuria, you should go to the hospital in time to exclude the possibility of urinary system tumor.