Men who urinate dark red without pain consider that it may be hematuria. It may be caused by stones, tumors, urethral trauma and so on. 1. Stones: generally related to the person’s living and eating habits, environment, genetics and other factors. Typical manifestations include hematuria as well as pain, usually microscopic hematuria is common, and nausea, vomiting of digestive symptoms can also be seen; however, a small number of patients can be manifested as painless hematuria. 2. Tumor: Bladder cancer is the most common tumor in the urinary tract. Its causes are mainly related to smoking, long-term exposure to chemical products, etc. Typical symptoms include intermittent painless hematuria. 3. Trauma: Urethral trauma, especially anterior urethral trauma, is commonly manifested by urethral bleeding, i.e., blood coming out from the urethral orifice, hematuria, pain in urination, difficulty in urination and other symptoms. Treatment includes prompt insertion of a catheter and urethral end-to-end anastomosis if there is a break in the urethra. The above symptoms may also be caused by other factors, the specific causes also need to go to the regular hospital and diagnosis and treatment, do not blind treatment.