The possible causes of red urine in men are: first, the use of red pigmented food or the use of rifampicin capsules can cause red coloring of the urine. This is not accompanied by any conscious symptoms, the urine routine examination does not contain red blood cells, after stopping the relevant food and drug intake urine color can return to normal. Second, when there is a urinary tract infection, there can be changes such as congestion and bleeding in the mucous membrane of the urinary tract. This can be accompanied by frequent urination, urgent urination and painful urination. It is necessary to conduct routine urine examination and urine culture examination to confirm the diagnosis. Thirdly, if there are stones in the urinary system, such as kidney stones, ureteral stones, etc., hematuria can occur, accompanied by pain in the area where the stones are located, back pain, abdominal pain, etc. Ultrasound examination of the urinary system is needed to confirm the diagnosis. Fourth, suffering from urinary tumor, such as kidney tumor, bladder tumor, etc. can cause urine bleeding. In the early stage, the pain is not obvious, and only the color of urine is red. Later, when the tumor increases in size, it can produce painful symptoms.