Leukocytes in Urine: Causes, Symptoms, Diagnosis & Treatment

Leukocytes, also known as white blood cells (WBCs), play an important role in your immune system. However, high levels of leukocytes in the urine can indicate an underlying problem with your urinary system. This article will discuss leukocytes in urine causes, symptoms, and treatment.

What are Leukocytes?

Leukocytes are a type of white blood cell that is part of your immune system. They help defend the body against infection and other foreign invaders. There are several different types of leukocytes, each with their own functions:

  • Neutrophils: These are the most common leukocyte and are one of the first cell types to arrive at the site of infection. Neutrophils help destroy bacteria and other pathogens.
  • Eosinophils: Responsible for combating multicellular parasites and infections. They also play a role in allergic reactions.
  • Basophils: Release histamines and other chemicals that are involved in inflammatory responses.
  • Lymphocytes: Includes both T cells and B cells that target specific pathogens and help activate the adaptive immune system.
  • Monocytes: These largest types of white blood cells ingest and destroy pathogens and dead cells. They differentiate into macrophages that act as scavengers.

Normally, just a small number of leukocytes are present in urine. An excess amount indicates inflammation or infection somewhere in the urinary tract. When damage or microbial invasion occurs, leukocytes will be released from the bloodstream and travel to the site to fight infection.

Leukocytes produce chemicals to destroy invading pathogens. They also call in additional defender cells and stimulate other immune responses. These actions help fight and limit the infection.

Leukocytes in Urine
Leukocytes in Urine

What Causes Leukocytes in Urine?

There are several possible causes for leukocytes showing up in the urine:

1. Urinary Tract Infections

One of the most common reasons for high leukocyte levels is a urinary tract infection (UTI). UTIs occur when bacteria enter the urinary tract and multiply, most often in the bladder or urethra. Typical UTI symptoms include:

  • Burning sensation when urinating
  • Frequent urge to urinate
  • Cloudy, bloody, or foul-smelling urine
  • Pelvic pain or pressure
  • Low grade fever in some cases

If left untreated, the infection can spread up to the kidneys and become even more serious. Once it reaches the kidneys, it is called pyelonephritis. Kidney infections come with additional symptoms like high fevers, chills, nausea and vomiting.

UTIs are more common in women due to their shorter urethras. Risk factors include pregnancy, diabetes, urinary catheters, family history, and recent sexual activity. Those with weaker immune systems also have an increased UTI risk.

2. Kidney Infections

A kidney infection, also called pyelonephritis, can also lead to increased leukocytes. Bacteria enter the kidneys from the bloodstream or spread from another part of the urinary tract, like an untreated bladder infection. In addition to the usual UTI symptoms, kidney infections may cause:

  • Fevers and chills
  • Pain in the back, side, or groin
  • Nausea and vomiting
  • Confusion or mental changes (in severe cases)

Kidney infections require prompt medical treatment. Some people may need hospitalization for IV antibiotics and fluid administration.

3. Kidney Stones

Kidney stones are solid deposits of minerals and salts that form in the kidneys. They can cause blockages in the urinary tract that obstruct the normal flow of urine. This obstruction leads to a buildup of bacteria, inflammation, and higher leukocyte levels as the body reacts to the stone. Symptoms of kidney stones include:

  • Severe pain in the back, side, lower abdomen, or groin
  • Pain that comes and goes in waves, increasing and decreasing in intensity
  • Pink, red, or brown urine from blood mixing
  • Cloudy or foul-smelling urine
  • Nausea and vomiting
  • Frequent need to urinate

Small stones may pass naturally, while larger ones sometimes require surgical removal. Medications can help relax the ureter to allow a stone to pass.

4. Tumors

Both cancerous and non-cancerous growths in the kidneys, bladder, or reproductive organs can sometimes increase leukocytes. As tumors expand, they can block the normal flow of urine and cause accumulation of bacteria. The leukocytes are released as the body reacts to the resulting infection.

Symptoms depend on the tumor size and location but may include:

  • Visible blood in the urine
  • Unexplained weight loss
  • Low back or abdominal pain
  • Swelling in the legs or abdomen

Diagnostic tests like CT scans and cystoscopy can identify tumors. Cancerous ones require specialized treatment plans.

5. Interstitial Cystitis

Interstitial cystitis (IC) is a chronic inflammatory condition affecting the bladder walls. It leads to scarring and reduced bladder capacity. Symptoms include bladder pressure, pelvic pain, and frequent urination. While not an infection, IC can cause inflammation and leukocytes in urine.

6. Autoimmune Disorders

Autoimmune conditions like lupus, rheumatoid arthritis, and Sjogren’s syndrome can sometimes spread inflammation to the kidneys and urinary tract. This results in elevated leukocyte counts as the immune system attacks the body’s own tissues.

7. Medication Side Effects

Certain medications like antibiotics, chemotherapy drugs, and some older diuretics have leukocytes as a potential side effect. Always review your medications with your doctor and report any urinary symptoms.

8. Other Causes

Less common causes of leukocytes in urine include:

  • Tuberculosis
  • Radiation therapy
  • Kidney damage from high blood pressure or diabetes
  • Bladder cancer
  • Sexually transmitted infections like chlamydia and gonorrhea
  • Structural problems causing urine backflow

Symptoms of High Leukocytes

The symptoms associated with excess leukocytes depend on the underlying condition. With a simple bladder infection, you’ll likely experience the usual UTI signs like burning with urination, pelvic discomfort, and foul-smelling urine.

Kidney infections, stones, and blockages more commonly cause back pain, nausea, vomiting, and fever along with urinary symptoms. Advanced kidney infections may also lead to mental status changes like confusion.

Tumors can cause blood in the urine, swelling, or lower back pain. Interstitial cystitis mainly causes bladder pressure and pain. In some cases, there may be no symptoms at all. Leukocytes are sometimes found incidentally through tests done for other reasons.

The only way to determine the exact cause is through proper diagnosis from your doctor. Notify them of any urinary symptoms you experience.

Diagnosing High Leukocytes in Urine

If urinary symptoms are present, your doctor can check for increased leukocytes through a urine test called a urinalysis. This simple test is done in a lab and checks your urine for:

  • White blood cells
  • Red blood cells
  • Bacteria
  • Proteins
  • Crystal deposits

To evaluate the urine, both a dipstick test and microscopic examination are performed. The dipstick has special chemicals that change color in response to leukocytes and other substances. Under a microscope, technicians will count the number of white blood cells per high power field (WBC/HPF).

Normal urine should not contain more than 10 WBCs/HPF. Levels between 10-100 cells often indicate inflammation like a developing infection. Over 100 cells usually signals an active infection.

Treating High Leukocytes in Urine

The treatment will depend on the underlying cause of the leukocytes detected on urinalysis.

1. Urinary Tract Infections

For simple UTIs, antibiotics are used to clear the infection and resolve the excess leukocytes. Some common antibiotics used include:

  • Trimethoprim-sulfamethoxazole (Bactrim, Septra)
  • Amoxicillin
  • Ciprofloxacin (Cipro)
  • Nitrofurantoin (Macrodantin, Macrobid)
  • Cephalexin (Keflex)

Your doctor will select the most appropriate antibiotic based on the bacteria identified on a urine culture as well as your medical history and drug allergies. It is important to take the full course as prescribed, usually 3-7 days. Stopping early can lead to recurring infection and leukocytes.

Make sure to drink plenty of fluids when taking antibiotics to help flush the urinary tract. Acetaminophen (Tylenol) or ibuprofen (Advil) can help relieve discomfort associated with the UTI. Seek prompt medical attention if symptoms worsen or fever develops, as this may indicate progression to a kidney infection.

For recurrent UTIs, your doctor may prescribe a low dose antibiotic to take daily or after sexual activity to prevent infection. There are also some UTI vaccines being developed that may be available in the coming years.

2. Kidney Infections

Kidney infections require close monitoring and intravenous (IV) antibiotic treatment, usually with hospitalization. Antibiotics often need to be given for 2 weeks or longer to fully clear a kidney infection. In severe cases, a kidney infection can lead to sepsis, a life-threatening immune response.

Common IV antibiotics used for kidney infections include:

  • Piperacillin/tazobactam (Zosyn)
  • Imipenem (Primaxin)
  • Ceftriaxone (Rocephin)
  • Cefepime
  • Vancomycin (for highly resistant infections)

In addition to antibiotics, hospital care involves IV hydration and medications to control nausea or vomiting. Your kidney function and urine output will be monitored. Once the infection is under control and you are stable, you will usually transition to oral antibiotics to finish the course at home.

3. Kidney Stones

For most kidney stones, pain relievers and drinking plenty of fluid to flush the urinary tract will help ease symptoms while waiting for it to pass. Medications to relax the ureter such as tamsulosin (Flomax) or nifedipine may sometimes facilitate stone passage.

Larger stones that fail to pass may need extracorporeal shock wave lithotripsy. Sound waves are used to break up the stones into smaller pieces that can then be flushed out in urine. Surgery may also be required for very large kidney stones causing persistent obstruction.

Getting to the root cause of recurrent kidney stones allows prevention of future issues through diet and lifestyle changes. Your doctor can provide specific advice based on the mineral composition of your stones. Addressing any underlying condition, like an overactive parathyroid, is also important.

4. Tumors

Both malignant and benign masses require tailored treatment plans coordinated by your oncology specialists and urologist. Surgery is often the first step to remove tumors in the bladder, kidney, or ureters. Minimally invasive laparoscopic techniques allow a shorter recovery in many cases.

Cancerous tumors will likely require additional interventions such as chemotherapy, radiation therapy, or immunotherapy medications. For metastatic cancers, systemic treatments to reach cancer at distant sites are necessary. Participating in clinical trials may give access to newer medications.

Close follow up is key after treatment to monitor for recurrence and ensure leukocyte levels normalize. Lifestyle changes like quitting smoking may also be recommended. With an early diagnosis and proper management, many bladder and kidney cancers have good outcomes.

5. Interstitial Cystitis

Treatment for interstitial cystitis focuses on relieving symptoms and preventing bladder irritation. Oral medications like amitriptyline, cimetidine (Tagamet), or pentosan polysulfate (Elmiron) help control pain and frequent urination. Nerve stimulators placed in the ankle or back can also modulate pelvic pain signals.

Installing liquid solutions like dimethyl sulfoxide into the bladder (a procedure called instillation) can temporarily relieve inflammation. Dietary changes to avoid trigger foods and beverages may help too. Stress management and pelvic floor therapy provide additional ways to minimize symptoms. Finding the right combination of lifestyle adaptations and medications gives patients with interstitial cystitis the best quality of life.

How to Prevent Leukocytes in Urine?

In addition to medical treatment, maintaining good personal hygiene and eating a proper diet can help resolve high leukocyte counts and prevent recurrent issues.

Personal Hygiene Tips

  • Drink at least 8 glasses of water daily to flush bacteria from the urinary tract. Stay well hydrated.
  • Urinate as soon as you feel the urge and empty your bladder fully. Holding urine allows bacteria to proliferate.
  • Shower instead of taking baths, which can introduce bacteria into the urethra.
  • Wash the genital area with mild unscented soap and water before and after sex. Rinse well.
  • Urinate shortly after sexual intercourse to flush away any bacteria that may have entered.
  • After bowel movements, always wipe from front to back to avoid spreading germs from the rectum to urethra.
  • Avoid using feminine hygiene sprays, powders, and deodorants which can irritate the urethra.
  • Wear cotton underwear and loose, breathable clothing. Avoid tight pants or pantyhose.
  • Change pads and tampons frequently during menstruation to keep the area clean.
  • Consider taking showers instead of baths during menstruation to avoid soaking in bacteria.
  • Avoid holding urine for prolonged periods of time. Go when you need to.
  • Practice safe sex by using condoms and dental dams to reduce transfer of bacteria.

Dietary Tips

  • Drink cranberry juice, which may help prevent bacteria from adhering to the bladder wall.
  • Increase your vitamin C intake with fruits and veggies to support the immune system.
  • Choose yogurt with live active cultures to introduce healthy bacteria into the body.
  • Stay hydrated by sipping water throughout the day. Dehydration concentrates urine allowing bacterial growth.
  • Avoid excessive alcohol and caffeinated beverages like coffee, tea, and soda which can irritate the bladder.
  • Don’t consume excess salt, which can increase calcium excretion and raise stone risk.
  • Eat more fiber and less meat to keep your digestive system regular and avoid straining with bowel movements.
  • Consider probiotic supplements to support your urinary microbiome and maintain healthy bacterial balance.
  • Discuss any necessary dietary changes with your doctor or nutritionist to ensure a balanced approach.

Following good hygiene habits and making supportive dietary choices aid in clearing up leukocytes while also preventing recurrent UTIs, kidney infections, and other problems.

When to See a Doctor?

You should make an appointment with your doctor if you notice any of the following:

  • Fever over 101°F
  • Pain in your back, side, abdomen, groin or pelvis
  • Burning feeling when urinating
  • Increased urinary frequency or sudden urges to urinate
  • Cloudy, odd-smelling, or dark urine
  • Visible blood in urine
  • Pain with sexual intercourse
  • Confusion, drowsiness or mental changes

Seek prompt medical attention for symptoms of a kidney infection like chills, high fever, vomiting, or severe pain. Call 911 or go to emergency if symptoms are progressing rapidly or you are unable to urinate.

Even mild symptoms should not be ignored, as early treatment is key to preventing a more serious kidney infection. Let your doctor know about any urinary symptoms at your next visit.


1. Can you have leukocytes without an infection?

Yes, it is possible to have leukocytes without a bacterial infection, called sterile pyuria. Causes include kidney stones, bladder cancer, autoimmune disorders, sexually transmitted infections, and interstitial cystitis.

2. Do leukocytes always mean a UTI?

Not necessarily. While it can signal a urinary infection, leukocytes may also occur due to physical obstructions like stones. Medications and conditions like lupus can lead to them without infection too.

3. What are normal leukocyte levels in urine?

Normal urine should contain less than 10 leukocytes per high power field (WBC/HPF). Levels 10-100 typically indicate inflammation, while over 100 leukocytes usually signals an active infection.

4. Can kidney disease cause leukocytes in urine?

Yes, kidney disorders like glomerulonephritis or IgA nephropathy can cause inflammation that leads to leukocytes in urine. Kidney damage allows white blood cells to leak into the urine.

5. Can stress cause leukocytes?

No direct connection between stress and leukocytes has been found. Extreme physical stress may potentially reduce immune response temporarily. But leukocytes in urine still warrant medical evaluation, even if stress could be playing a role.

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