These cells are produced or stored in various locations throughout the body, including the thymus, spleen, lymph nodes, and bone marrow.
High leukocyte levels suggest that the body is trying to fight an infection.
Leukocytes travel throughout the body, moving between the organs and nodes and monitoring any potentially problematic germs or infections.
Only very low levels of leukocytes, if any, are normally found in the urine. A high leukocyte content in the urine may indicate an infection or other underlying inflammatory medical problems.
This article will look at five common causes of leukocytes in the urine.
Leukocytes might be present in urine for a range of reasons.
1. Bladder infections
A high number of leukocytes in the urine may indicate the presence a urinary tract infection.
A urinary tract infection (UTI) is one of the most common causes of leukocytes in the urine. A UTI is an infection that occurs in any part of the urinary system.
This system includes the kidneys, ureters, bladder, and urethra. Most infections involve the lower urinary tract, and more specifically the bladder and urethra.
Most commonly, a UTI occurs when a bacterium or bacteria enter the urinary tract by way of the urethra and begin to multiply in the bladder.
A UTI in the urinary bladder can spread to the ureters and kidneys without prompt treatment, and this can become serious.
2. Kidney stones
A higher-than-usual number of leukocytes may be a sign of kidney stones.
Urine normally contains lower levels dissolved minerals and salts. People with high levels of these in their urine are at risk of developing kidney stones.
- nausea and vomiting
- fever and chills
Stones that make their way into the ureters can interfere with the forward movement of urine. This blockage can allow bacteria to build up more easily and lead to an infection.
3. Kidney infection
A kidney infection can increase levels of white blood cells in the urine.
These infections often start lower in the urinary tract and spread up to the kidneys. Though less common, it is also possible for bacteria from other areas in the body to spread through the bloodstream to the kidneys.
People with weak immune systems or who have been using urinary catheters for long periods face a higher risk of developing a kidney infection.
4. Urinary system blockage
A blockage can lead to the development of hematuria, which is blood in the urine, or hydronephrosis, which is fluid around the kidney or kidneys.
The blockage can be due to trauma or caused by kidney stones, tumors, or other foreign material.
5. Holding in urine
There is a reason why people should not make a habit of holding in their urine.
Holding in urine for extended periods of time can weaken the bladder and make it difficult to empty. If urine spends too long building up in the bladder, bacterial presence and possible infection can more easily occur.
This infection can lead to higher levels of leukocytes in the urine.
White blood cells help all parts of the body fight infection.
These are just a few of the common causes, but there are others. The following can also cause raised levels of leukocytes in the urine:
- some cancers, such as prostate, bladder, or kidney cancer
- blood diseases such as sickle cell anemia
- some pain relieving medicines
- interstitial cystitis
Leukocytes in the urine cause different symptoms for different people, but there are a few symptoms or signs that suggest leukocytes may be present in the urine.
One of the most visible signs is cloudy or foul-smelling urine. Other signs include frequent urination, a pain or burning sensation when passing urine, or the presence of blood in the urine.
Other symptoms include:
- shivering and fever
- lower back and side pain
- acute pelvic pain
- nausea or vomiting
- long-term pelvic pain
- painful sex
People who notice any of the above symptoms should contact their doctor for further examination.
A urine analysis (urinalysis) is used to screen the urine for abnormalities and may be enough to detect any problems.
People who suspect leukocytes in the urine provide a urine sample that their doctor can analyze in three ways: Visual exam, dipstick test, and microscopic exam.
A dipstick test will detect any unusual substances in the urine.
- Visual exam: Technicians examine the appearance of the urine. Cloudiness or an unusual odor may signal an infection or another potential problem. The food that a person eats can also affect urine color.
- Dipstick test: A thin, plastic stick with strips of chemicals is placed in the urine to detect any abnormalities. The chemicals on the strip will change color to indicate if certain substances are present.
- Microscopic exam: Drops of urine are examined under a microscope. The presence of leukocytes might be a sign of infection.
Urinalysis is the first stage of testing.
If blood or other substances are present in the urine, the physician may perform more tests to identify the cause of the problem.
The problem may be any of the conditions listed above or a more serious noninfectious illness, such as a blood disorder, autoimmune disease, or cancer. The doctor will order additional tests as needed.
It is possible to have white blood cells in the urine without a bacterial infection. Sterile pyuria refers to the persistent presence of white blood cells in the urine when no bacteria are found to be present by laboratory examination.
According to The New England Journal of Medicine, 13.9 percent of women and 2.6 percent of men are affected by this condition. Certain sexually transmitted diseases, viral or fungal infections, or even tuberculosis can cause sterile pyuria.
A correct diagnosis is vital for identifying a path of treatment.
Treatment for leukocytes in the urine depends on the cause and if there is an infection. For some conditions, such as a bacterial UTI, antibiotic therapy will clear up the infection relatively quickly.
For more severe infections or those that will not resolve easily, more in-depth medical treatment may be needed. In some cases, hospitalization may be necessary.
Lifestyle changes can help reduce the symptoms of some conditions that cause leukocytes to enter the urine.
- drinking more water
- urinating when you have to go
- staying as healthy as you can
Taking acetaminophen, ibuprofen, or prescription drugs may also help to ease pain in the urinary system.