How do they find out if I have a uti?

Urinalysis and. Urine culture. Positive nitrite test on urine indicates high probability of a uti. Bacteria can be seen by performing microscopy on a spun specimen of urine. Urine culture from a clean mid void specimen that grows >50, 000 colonies/ml of a single organism is a very reliable test. Good luck.
Urinalysis & culture. They first look for the presence of white blood cells in the urine, as part of a urinalysis. The urine leukocyte esterase test may also be positive. A urine culture confirms the diagnosis, and also tells you which bacteria are causing the infection, and which antibiotics can be used for treatment.