White blood cells (WBCs) in urine are our strongest suggestion that there’s an infection (UTI). However, if WBCs that happen to be in the vagina or under the foreskin wind up washed into the urine, the urine dipstick exam can’t tell the difference. A urinalysis by microscope can help decide, but that’s often not available.
So it’s important, especially for women, to give a “clean catch,” which is more than just wiping with a towelette. We spend a minute or so explaining step-by-step as follows:
- We want to know what germ is inside you, not on the skin. So try as hard as possible that the urine doesn’t touch the skin.
- Women — Spread your legs real wide apart, & hold the labia apart. Clean them with the towelette, but don’t let go. Men — Retract the foreskin, then clean with towelette.
- Start to pee in the toilet to wash outside germs away, then without stopping, catch some directly into the cup. Finish peeing in the toilet.
- Try real hard to make sure the urine doesn’t touch the skin.
I’ve heard people tell women to, “wipe from front to back,” which makes absolutely no difference at all. Wipe yourself however you want.
A truly clean-catch urinalysis that’s positive for WBCs means there’s an infection: either a common bladder infection (cystitis), or more serious kidney infection (pyelonephritis), or maybe a urethral infection from chlamydia (or even gonorrhea). A negative for WBCs means no urinary infection.