Leukocyturia R82.8

Leukocyturia is defined as the detection of > 10 leukocytes/µl in the urine. If the urine takes on a yellowish color due to a large number of leukocytes, this is referred to as pyuria (Herold 2025).

Leukocyturia is most commonly caused by acute or chronic cystitis (Hofmann 2014). Balanitis and vulvitis must also be ruled out (Fegeler 2025).

If leukocyte casts are also detected, this suggests a renal origin, most commonly due to pyelonephritis (Herold 2025).

Recurrent leukocyturia should always be evaluated by a urologist (Kempinski 2021).

Leukocyturia can be detected by identifying leukocytes in the urine using test strips. This results in a positive reaction of the urine to indoxyl esterase. If the test strip yields two positive results, this indicates the presence of more than 8 leukocytes (granulocytes) per µl (Frank 2021).

The detection limit of the test strips is approximately 20 leukocytes per µl of urine. In women, however, the sensitivity is significantly lower, as fluoride can cause false-positive results in up to 40% of cases (Herold 2025).

The diagnosis is made based on the patient’s medical history, a urine test using a test strip, and subsequent microscopic and microbiological examination of the urine to detect bacteria (Antwerpes 2025).

Antibiotic therapy based on the antibiotic susceptibility test.

1. Antwerpes U et al. (2025) Leukocyturia. Doc Check Flexikon. https://flexikon.doccheck.com/de/Leukozyturie
2. Fegeler U, Rodens K, Weiß-Becker C (2025) Practical Handbook of Primary Pediatric Care. Elsevier Urban and Fischer Verlag 382
3. Frank H et al. (2021) Interdisciplinary S2k Guideline “Rational Laboratory Diagnostics for the Evaluation of Acute Kidney Injury and Progressive Kidney Disease 2021”; AWMF Registry No. 115/001
4. Herold G et al. (2025) Internal Medicine. Herold Verlag 599
5. Hofmann W, Aufenanger J, Hofmann G (2014) Clinical Handbook of Laboratory Diagnostic Pathways: Introduction, Screening, Stepwise Diagnostics. Walter de Gruyter GmbH Berlin / Boston 143–145
6. Kasper D L, Fauci A S, Hauser S L, Longo D L, Jameson J L, Loscalzo J et al. (2015) Harrison’s Principles of Internal Medicine. McGraw-Hill Education
7. Kempinski S (2021) Accurately Diagnosing Kidney Damage Using Blood and Urine Tests. Medical Tribune https://www.medical-tribune.de/medizin/urologie/nierenschaeden-ueber-blut-und-urin-richtig-diagnostizieren

8. Staubach K. H., Straub L., Kreutzig T., Guzek B., Limberger A. (2008) Concise Textbook: A Four-Subject Series on Minor Surgical Specialties—Urology, Ophthalmology, ENT, Orthopedics. Elsevier Urban & Fischer Verlag, Munich / Jena 17