Leukocytes are white blood cells essential to the human immune system that defend the body against infection.
Leukocytes circulate through tissues and blood streams to work against unknowing agents entering the body by attacking them and thus responding to illness or injury.
White blood cells comprise 1% of our blood. The usual range of leukocytes in urine is about 0-5 WBC/hpf.
The presence of white blood cells in high amounts in urine indicates urinary tract infection, kidney damage, blood cancer, or pyuria (pus in urine).
Moreover, kidney stones, pelvic tumors, or any urinary tract blockage can also cause leukocytes to appear in urine more than at normal levels.
Further investigations are usually done to reach the main cause of leukocytes in urine.
Keep reading to learn more about what causes leukocytes in urine, including treatment options, accompanying symptoms, diagnosis, and prevention tips.
What are leukocytes?
White blood cells, also known as leukocytes or leucocytes, are an essential part of the immune system and work to fight against viruses, bacteria, fungi, and other disease-causing organisms.
They defend the body through different mechanisms. For example, some cells directly engulf the bacteria while others produce antibodies – a special chemical to kill the bacteria or viruses.
Bone marrow is the main site of WBC production, and the organs such as the kidney, spleen, and liver regulate and mature leukocytes.
Usually, leukocytes are classified into the following types:
- Neutrophils: First one to act against infection by causing local swelling.
- Lymphocytes: The second largest group of WBCs to work against infection, including T lymphocytes or B lymphocytes.
- Monocytes and Macrophages: These can engulf bacteria and convert them into waste products, thus removing them from the body.
- Eosinophil: Eosinophils provide protection against parasites.
- Basophil: This comprises less than 1% of white blood cells and provides protection against allergens, parasites, and infections.
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What causes leukocytes in urine?
There are many reasons of leukocytes appear in urine, such as:
Urinary tract infection
The urinary tract includes the kidney, bladder, and ureters (the tubes which contain urine from the kidney to the bladder).
If the urinary tract gets infected, there is a high chance of having leukocytes in urine.
If leukocyturia occurs due to an underlying UTI, the following UTI symptoms may present:
- Pain in the abdomen or back
- Vomiting or nausea
- Painful urination or burning when peeing
- Bad-smelling urine
- Cloudy urine
- Frequent urination
Inflammation due to injury, disease, or infection can increase the production and release of leukocytes, resulting in leukocytes in urine.
Urinary tract inflammation occurs due to cystitis (inflammation of the bladder) or interstitial nephritis (the organ kidney gets infected). Bladder inflammation can occur without interstitial nephritis.
This may cause issues like:
- Feet swelling
- Recurrent urination
- Painful and foul-smelling urination
- Hematuria (blood in urine)
All these symptoms are accompanied by inflammation.
Buildup of calcium and other minerals in urine makes crystal stones in the kidney. The size varies from a pea to a golf ball. The larger the kidney’s stone, the more it causes blockage of urine passage.
This can cause the following issues:
- Belly pain or pain in the groin, back, or side
- Urine with blood that appears red, brown, or pink
- Pee urgency
- Painful urination
- Cloudy or bad-smelling urine
Some pain-relieving medicines or others, such as antibiotics, corticosteroids, aspirin, or diuretics, cause leukocytes to appear in the urine.
Autoimmune diseases like Systemic Lupus Erythematosus (SLE) can cause white blood cells to appear in the urine in large amounts, with protein and erythrocytes.
This condition usually presents with inflammation of the eyes, skin, joints, and kidneys.
Prostate, kidney, bladder, or prostate cancer causes a weak immune system, thus increasing white blood cells in the urine. Sometimes WBCs in urine appear as a result of cancer treatment.
Who is at an increased risk?
Women have a higher risk for leukocyturia in urine than men because there is an increased incidence of urinary tract infections among women, especially when pregnant.
Among men, leukocytes in urine can occur more frequently in those with enlarged prostate or other obstructive urinary problems. A poor immune system can also increase the risk of leukocytes in urine.
Possible accompanying symptoms
White blood cells, if present in urine, usually do not cause any symptoms on their own unless present in large amounts.
Usually, the conditions in which WBCs appear in the urine in large quantities present with the following generalized symptoms:
- Chills or fever
- Body pain
- Recurrent Infection
- Dysuria (painful urination)
- Hematuria (blood in urine)
- Constant cough
- Difficult breathing
Leukocyturia in urine can occur in many diseases, as mentioned above. Hence, it is essential to diagnose the underlying cause so it can be treated accordingly.
The following tests can help diagnose leukocyturia as well as an underlying cause:
- Urinalysis (urine analysis) is done at chemical, physical and microscopic levels. Usually, urinalysis can clearly indicate leukocytes in urine.
- Urine dipstick test is a screening test to detect the presence of white blood cells in urine and urinary tract infections. If the test is positive, urine is usually observed under a microscope for WBCs, RBCs, and proteins.
- An X-ray or ultrasound KUB (Kidney, Ureter, Urinary Bladder) can be done to diagnose kidney and ureteric stones.
- CBC (a complete blood count) to check the levels of WBCs in the blood.
Treatment of leukocyturia mainly depends upon the underlying cause.
- Obstruction treatment: A surgical procedure may be required to treat obstruction caused by a renal stone or tumor. If the stone is small, drink plenty of liquid, as passing out the stone is a complex process. For tumors, radiation and chemotherapy can also be done.
- UTI treatment: Antibiotics are suggested to treat bacterial infections. A short course of antibiotics is needed to treat UTI. Still, if it happens to you frequently, a long span of antibiotics is required along with antibiotics to increase the fluid intake to excrete a UTI. It may cause excessive urination but will enhance the healing process.
- Over-the-counter medicine: Use pain-reducing medicine such as ibuprofen if the pain is also associated with leukocyturia.
Preventing leukocytes in urine
The following measures can help prevent leukocyturia or underlying diseases that cause it.
- Stay hydrated: Drink plenty of water to help remove debris, infectious particles, and small stones in the kidney.
- Cranberry juice: Eating cranberries or drinking cranberry juice is helpful to prevent a UTI. Cranberries have proanthocyanidins that work against UTI and do not allow bacteria to stick to the urinary tract.
- Personal hygiene: Maintain good personal hygiene to avoid UTI or kidney stones, which are the common causes of leukocytes in urine. Wash your hands properly after using the toilet and thoroughly wipe the area with water.
- Enhance immunity: Try to have a balanced diet, proper sleep, and regular physical activities to boost your immune system to avoid infections. Take vitamins or supplements to enhance immunity.
- Frequent urination: Avoid holding urine and urinate when you feel the urge.
- Avoid triggers: If the cause of leukocyte is UTI, try to avoid irritants such as perfumed soaps, harsh washing, or sanitary pads that cause UTI.
Leukocytes are also called white blood cells that fight against pathogens and foreign invaders as a part of the immune system.
A high level of WBCs in the urine, known as leukocyturia, indicates the presence of UTI, kidney stones, or infection. It may also occur due to cancers or medication used to treat cancer.
Treatment involves managing the underlying conditions. Prevention can be done by maintaining personal hygiene, safe sexual activity, proper sleep, immunity-boosting foods, and regular physical activities.