Smoking is the most certain risk factor for bladder cancer. About 30%-50% of bladder cancers are caused by smoking, and smoking can increase the risk rate of bladder cancer by 2-4 times, and the risk rate is proportional to the intensity and duration of smoking. The etiology of kidney cancer is not known. Its development is related to genetics, smoking, obesity, hypertension and anti-hypertensive treatment. Not smoking and avoiding obesity are important ways to prevent the development of kidney cancer.