Finding leukocytes, or white blood cells, in a urine test often prompts concern about a urinary tract infection (UTI). When a person is also experiencing a yeast infection (candidiasis), it is natural to wonder if the two findings are connected. The question of whether a vaginal yeast infection can cause leukocytes to appear in the urine centers on understanding the body’s immune response and the mechanics of collecting a urine sample.
What Leukocytes in Urine Indicate
Leukocytes are white blood cells, a major component of the body’s immune system, circulating throughout the bloodstream and tissues to defend against foreign invaders. When found in higher-than-normal amounts in the urine, a condition known as leukocyturia or pyuria, it signals that an immune response is underway. A normal urine sample typically contains fewer than five white blood cells per high-powered field (WBC/HPF). Detecting elevated levels suggests inflammation or infection somewhere along the urinary tract, which includes the kidneys, ureters, bladder, and urethra. While the most common cause is a bacterial urinary tract infection (UTI), this finding requires further investigation to pinpoint the exact location and cause of the inflammation.
How a Yeast Infection Influences Urine Test Results
A vaginal yeast infection, caused by the overgrowth of the fungus Candida, triggers a localized inflammatory response in the vaginal and vulvar tissues. This immune activity occurs externally to the urinary tract but in close anatomical proximity to the urethra. The presence of leukocytes in the urine during a yeast infection is most often due to sample contamination rather than a true urinary tract infection. As the urine passes through the inflamed genital area during collection, it can pick up white blood cells, discharge, and yeast, leading to a false positive result. To avoid this misleading result, a “clean-catch midstream” collection technique is necessary, which involves carefully cleaning the genital area and collecting only the middle portion of the urine stream.
Other Common Causes of Leukocytes in Urine
While sample contamination from a yeast infection is a frequent cause of leukocyturia, a positive result warrants consideration of other common and more clinically significant conditions. The most frequent genuine cause is a bacterial urinary tract infection, or cystitis, which is typically accompanied by symptoms like painful or frequent urination. If the infection has progressed to the kidneys, a condition called pyelonephritis, the leukocyte count will be high and often accompanied by systemic symptoms such as fever, chills, and flank pain.
Leukocytes can also be present in the absence of bacteria, a condition known as sterile pyuria, which suggests non-bacterial causes. These causes can include certain sexually transmitted infections (STIs) like chlamydia or gonorrhea, which may not cause typical UTI symptoms but still trigger an immune response in the urinary tract. Other potential causes are inflammatory conditions like interstitial cystitis or the presence of kidney stones, which can cause irritation and obstruction that leads to increased white blood cells in the urine. Persistent or unexplained leukocyturia requires further testing, such as a urine culture, to differentiate between contamination, a bacterial infection, or a non-infectious inflammatory process.