Leucocytes in urine (pyuria)
Normally, the level of white blood cells in urine is low, and its normal range is 0-5 WBC/HPF. But, if there is a high level of leucocytes in urine, this indicates that your body fights infection in the kidney or urinary tract (ureter, bladder, and urethra).
Causes of pyuria
1) Urinary tract infection (UTI) is the most common cause of high leucocytes in the urine, and it is more common in females.
2) Renal infections: infection may spread from the other parts of the body to the kidneys through the blood or spreads from the urinary tract.
3) Urinary obstruction: It may occur due to kidney stones or stones in the urinary tract, tumors, or trauma. It may lead to hematuria (blood in urine) or urinary tract infections.
4) Urine retention increases the chance of urinary tract infection.
Symptoms of pyuria
These symptoms depend on the cause and include:
- Fever
- Frequent urination and burning urination
- Cloudy and foul-smelling urine or hematuria
- Pelvic pain
- Nausea and vomiting
- Pain in one or both sides, back, or abdomen
Diagnosis of pyuria
If you have symptoms of urinary tract problems (infections or stones), your doctor will ask you to do a urine analysis. In urine analysis, your doctor will see the color, content (WBCs, RBCs, or bacteria), and concentration of urine. In pyuria, the urine is cloudy and contain leucocytes.
Also, the presence of nitrite or leukocyte esterase enzyme in the urine may be a sign of urinary tract infection, while proteinuria is a sign of renal disease.
The presence of nitrite in the urine is specific for certain types of bacteria, such as E.coli. Thus, we may have high leucocytes in urine without nitrite, but the presence of infection remains possible. In this case, your doctor will ask for more investigations to detect the cause of leucocyte in the urine (infection or other diseases?).
