To find out the cause of blood in the urine, a man must see a doctor for a series of tests, according to Mayo Clinic. The doctor asks a series of questions, and then does a physical exam, urine test, imaging test or cystoscopy.
The physical exam is usually the first step in determining the cause of blood in the urine, and the doctor may ask a series of questions as well as talk about medical history, explains Mayo Clinic. A urine test may also occur, and this test helps the doctor to determine if the urine contains red blood cells, if there are bacteria in the urine or even minerals, which can cause kidney stones.
An imaging test is also often necessary to determine the cause of blood in the urine, reports Mayo Clinic. In this case, the doctor may suggest a CT scan or MRI. A doctor may also use ultrasound to get images of the bladder and kidneys. If it's possible that a disease has caused the blood in the urine, a doctor may also use a cystoscopy. To do this, the doctor inserts a narrow tube with a small camera into the bladder and urethra to look for signs of disease.