If you are concerned about a UTI, then you should contact your doctor. Frequently, you can be diagnosed and treated without going to your doctor's office. Ways to diagnose a UTI are via urinalysis and/or urine culture. A sample of urine is examined under a microscope by looking for indications of infection – bacteria or white blood cells in the urine. Your physician may also take a urine culture if needed. If you ever see blood in your urine, you should contact your doctor right away. Blood in the urine may be caused by a UTI but it may also be from a different problem in the urinary tract.