Leukocytes, or white blood cells, are a key part of the immune system, identifying and neutralizing foreign invaders. Their presence in urine, known as leukocyturia or pyuria, signals an underlying issue requiring medical evaluation. While a sign of the body’s protective response, it is not a diagnosis and indicates further investigation is needed.
Understanding Leukocytes in Urine
When infection or inflammation occurs in the urinary tract, white blood cells migrate to the affected area. Their presence indicates the immune system is actively responding. While a small number of white blood cells can be normal in urine, elevated levels suggest significant immune activation.
Primary Conditions Indicated by Leukocytes
Leukocytes in urine frequently point to an inflammatory or infectious process. Urinary tract infections (UTIs) are the most common cause, occurring when bacteria enter and multiply in the urinary tract. This includes bladder infections (cystitis) or kidney infections (pyelonephritis).
Kidney stones can also lead to leukocytes in urine. These mineral deposits can cause irritation, inflammation, or obstruction within the urinary tract. The body’s inflammatory response to the stone’s presence or to any secondary infection resulting from the blockage can cause white blood cells to appear in the urine.
Sometimes, leukocytes are found in urine even when standard bacterial cultures show no infection, a condition called sterile pyuria. This can be caused by sexually transmitted infections (STIs) like chlamydia or gonorrhea, which may not grow on typical bacterial cultures. Viral infections, certain medications, or systemic inflammatory conditions like interstitial cystitis, a chronic bladder condition, can also result in sterile pyuria.
Other conditions contributing to leukocytes in urine include inflammation of the prostate gland in men (prostatitis) or vaginal infections in women. Certain kidney diseases, such as glomerulonephritis, or even some cancers of the urinary tract like bladder or kidney cancer, can also lead to an increased presence of these cells. The body’s response to these conditions, whether infectious or non-infectious, involves an immune reaction that can release white blood cells into the urine.
Identifying the Cause: Symptoms and Tests
Individuals with leukocytes in their urine may experience a range of symptoms, depending on the underlying cause. Common indicators often include cloudy or foul-smelling urine, which can result from the presence of white blood cells and, if present, bacteria. Discomfort during urination, a frequent urge to urinate, or pain in the lower abdomen or back are also common.
To identify the cause, a healthcare provider typically performs a urinalysis, a comprehensive urine test. This process often begins with a dipstick test, which uses a chemically treated strip to detect substances like leukocyte esterase, an enzyme found in white blood cells. A positive result for leukocyte esterase suggests the presence of leukocytes.
Following a dipstick test, microscopic analysis of urine sediment is often performed to count the actual number of white blood cells. A count exceeding 5 white blood cells per high-powered field (WBCs/HPF) is generally considered elevated. If an infection is suspected, a urine culture may also be conducted to identify specific bacteria and determine their susceptibility to antibiotics.
Addressing the Underlying Issue: Treatment and Outlook
Treatment for leukocytes in urine is determined by the specific underlying condition identified through diagnostic testing. For bacterial infections such as UTIs, antibiotics are commonly prescribed to eliminate the bacteria. The duration and type of antibiotic depend on the severity of the infection and the specific bacteria identified.
If kidney stones are the cause, treatment may involve increasing fluid intake to help pass smaller stones or procedures to break up or remove larger ones. Conditions like interstitial cystitis might be managed with medications to reduce inflammation and pain, while sexually transmitted infections require specific antibiotic or antiviral therapies.
Consulting a healthcare professional for accurate diagnosis and tailored treatment is important. With appropriate medical intervention, most conditions that cause leukocytes to appear in urine are manageable. Early treatment can help prevent complications and improve overall outcomes.