Leukocytes in Urine: 6 Causes & What to Do

It is normal for there to be some leukocytes in the urine - usually 5 leukocytes per field or 10.000 leukocytes per ml of urine. Nonetheless, if there is a higher quantity of leukocytes it may be a sign of an infection, in the urinary or reproductive system, or a sign of other types of diseases like, lupus, kidney problems or cancer. 

When the amount of leukocytes in the urine is increased, it is advisable to make a urinalysis, which is a urine test that also indicates the amount of red blood cells, epithelial cells, microorganisms and proteins present in the urine, which can help to identify a diagnosis.

Leukocytes in Urine: 6 Causes & What to Do

Urine may get leukocytes due to several situations, such as:

1. Infection

A urinary tract infection is the main cause for the increase of leukocytes in the urine, which indicates that the immune system is trying to fight infection by fungus, bacteria or parasites. As well as large quantities of leukocytes, in the urine test, it is also possible to identify the presence of epithelial cells and the microorganism responsible for the infection. 

What to do: in case of an infection, it’s important for the doctor to request the urine culture test, which is a urine test that identifies which microorganism is responsible for the infection. The doctor will then recommend an appropriate treatment according to the situation. In the case of bacterial infection, the doctor may recommend antibiotics if the patient presents symptoms of infection, such as pain and burning when urinating as well as discharge. 

In the case of fungal infection, the doctor will prescribe antifungal medication, such as Fluconazole or Miconazole, according to the fungus identified. If parasites are what caused the infection, the most common protozoan involved is Trichomonas sp., which is treated with Metronidazole or Tinidazole, according to doctor supervision.

2. Kidney problems

Problems in the kidneys such as nephritis or kidney stones can also lead to leukocytes appearing in the urine. In addition, there may also be crystals in the urine or, sometimes, red blood cells.

Both nephritis and kidney stones may also present some characteristic symptoms such as back pain, difficulty peeing and decrease in the quantity of urine.

What to do: f you suspect you may have kidney stones or nephritis, it’s important you visit a G.P. or a urologist so that you can get an ultrasound and your urine tested. That way the doctor may be able to identify the reason for the increase in leukocytes in urine and start the adequate treatment.

3. Systemic Lupus Erythematosus

Systemic lupus erythematosus is an auto-immune disease, in other words, it’s a condition in which the immune cells attack the body, causing joint, skin, eye and kidney inflammation. In relation to lab tests, a urine test will evidence a high quantity of leukocytes and a CBC will also help with diagnosis. 

What to do: in order for the amount of leukocytes in the urine to decrease, the treatment for lupus will need to be done under doctor supervision. Usually a doctor will prescribe medication according to the symptoms presented by the patient, such as anti-inflammatory medication, corticosteroids, or immunosuppressive drugs. So, as well as being possible to decrease the quantity of leukocytes in the urine, it’s also possible to control lupus symptoms. 

Leukocytes in Urine: 6 Causes & What to Do

4. Use of medication 

Some types of medication, such as antibiotics, aspirin, corticosteroids, and diuretics can lead to the appearance of leukocytes in the urine.

What to do: if you are taking any type of medication that may be causing the increase of leukocytes in the urine, it’s important to communicate this alteration to the doctor that prescribed the medication.

5. Holding urine

Holding urine for large amounts of time can encourage the increase of microorganisms, resulting in a urinary tract infection and causing leukocytes to appear in the urine. In addition, if you hold urine for too long, your bladder will begin to weaken and will not empty completely. This causes urine to remain inside the bladder and microorganisms to proliferate. 

What to do: if you suspect this might be the cause, it’s important that you relieve yourself immediately after you feel like you need to pee, so that urine and microorganisms do not accumulate in your bladder. In addition, to prevent infections from occurring, it is recommended that you drink at least 2 liters of water a day.

6. Cancer

Although it is a rarer situation, the existence of bladder, prostate or kidney cancer can also lead to leukocytes appearing in the urine, as these conditions will lead to a weakened immune system. In addition, the presence of leukocytes can happen as a consequence of cancer treatment.

What to do: the presence of leukocytes in the urine is common in cancer that affects the urinary and genital systems. If this happens to you, your doctor will need to keep checking the amount of leukocytes in the urine in order to check the progression of the disease and your body’s response to treatment.

How to find out the amount of leukocytes in the urine 

The quantity of leukocytes in the urine is checked through macro and microscopic analysis to identify the presence of abnormal elements, such as crystals, epithelial cells, mucous, bacteria, fungi, parasites, leukocytes and red blood cells.

In a normal urinalysis it is common for there to be 0 to 5 leukocytes per field, and there may be higher amounts in women according to their age and menstrual cycle. When there are more than 5 leukocytes per field, this is indicated in the examination with the name "pyuria", which regards to the presence of large quantities of leukocytes in the urine. In these cases, it’s important for the doctor to relate the pyuria with other results in the urine test and with the results of the blood tests and the microbiological tests that he may have requested.

Before carrying out a microscopic test, the reagent test is done to indicate certain characteristics of the urine, including the leukocyte esterase, which is a reagent when there are a lot of leukocytes in the urine. Even though this signals pyuria, it’s important that the quantity of leukocytes seen in the microscopic test be communicated.

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  • STRASINGER, Susan K.; DI LORENZO, Marjorie S.. Urianalysis and body fluids. 5 ed. Estados Unidos: E. A Davis Company, 2008. 73-74; 94-95.
  • MAYO CLINIC. Urinalysis. Available on: <https://www.mayoclinic.org/tests-procedures/urinalysis/about/pac-20384907>. Access in 10 May 2019
  • MEDICAL NEWS TODAY. Why are there leukocytes in my urine?. Available on: <https://www.medicalnewstoday.com/articles/314165.php>. Access in 10 May 2019
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