Blood in urine in men is mostly seen in urinary stones, acute prostatitis, urinary tract infection, urological tumors, prostatic hyperplasia, nephrotic syndrome, glomerulonephritis, etc. Blood in urine is a common urological symptom, and there are many causes for its occurrence. The blood in urine caused by urinary stones is mostly accompanied by painful urination or kidney colic or back pain. In addition to painful urination, acute prostatitis can also cause urinary retention, pelvic pain and fever. Urinary tract infections can also produce blood in urine, mainly accompanied by bladder irritation symptoms, such as frequent, urgent and painful urination. The hematuria produced by urinary tract tumors is mostly painless carnal hematuria, which often has a relatively insidious onset. Once asymptomatic hematuria occurs, one must pay attention to it and be alert to the occurrence of tumors. In the elderly, prostatic hyperplasia, due to the congestion of the prostate mucosa and the expansion of the glandular hyperplasia, can cause hematuria, which may be accompanied by painful urination and incomplete urination, and can seriously produce large blood clots and lead to urinary retention. In internal hematuria such as nephrotic syndrome, the red blood cell pattern in the urine is mostly heterogeneous. As mentioned above, there are still many causes of blood in urine in men, commonly due to stones, tumors, urinary tract infections, and medical hematuria, so the treatment should be clearly diagnosed first and timely symptomatic treatment.