White blood cells in the urine may indicate a urinary tract infection, according to MedlinePlus. If white blood cells are found, a physician may request a microscope analysis to confirm the presence of an infection.
White blood cells travels throughout the body and detect the presence of bacteria, viruses and other intruders, according to the University of Rochester Medical Center. If a foreign invader is detected, white blood cells multiply and destroy foreign invaders and protect the body against illness.
If a physician suspects a urinary tract infection, he may order a leukocyte esterase urine test to detect the existence of white blood cells in urine, according to the MedlinePlus. Although a positive reading may indicate an infection, trichomoniasis and vaginal secretions may cause a false positive test result.
If white blood cells are present, a physician may request a urine culture to confirm an infection, according to the American Association for Clinical Chemistry. A urine culture detects the presence of bacteria. If the doctor finds disease-causing bacteria in the urine sample, susceptibility tests are performed to discover an antibiotic that treats the urinary tract infection. When a person has chronic urinary infections, a physician may also order tests to check for diabetes and altered kidney functioning.