Men with blood clots in urine may be caused by urinary tract infections, urinary tract stones, urinary tract tumors and other reasons. 1. Urinary tract infection: such as acute cystitis, urethritis, acute pyelonephritis. Inflammation irritates the mucous membrane, causing bleeding of the mucous membrane and formation of blood clots in the bladder to be discharged with urine. 2. Urinary stones: such as ureteral stones, bladder stones patients, in the stone damage to the ureter, bladder mucosa may lead to bleeding, blood coagulation appeared in the bladder and can be discharged with the urine, manifested as urine with blood clots. 3. Urological tumors: for example, patients with renal pelvis cancer may have hematuria with naked eyes, and blood clots will be formed when there is more bleeding; bladder tumor usually manifests as hematuria with naked eyes, and the symptom of blood clots in urine may also appear when there is more bleeding. When men have blood clots in urine, they should go to regular hospitals in time to find out the cause of the disease and give targeted treatment under the guidance of professional doctors.