pyuria bottle

Pyuria Definition

By its name, “Pyuria” literally means urine with pus. It is clinically defined as the presence of 6-10 or more neutrophils per high power field of voided urine caught midstream.

Pyuria is not a disease in its own sense. It is not a valid medical diagnosis which a layman may believe it to be. Rather, it is more of a finding proven by laboratory exam which indicates the presence of large amounts of white blood cells (WBC) or what we call leukocytes.

Pyuria happens when there is a bacterial invasion in the urinary system. Our body normally responds to tissue irritation through inflammation. This inflammatory response is manifested by an increase in the blood flow to that area, swelling of the tissues, and an invasion of WBCs to help fight the irritation. Therefore, inflammation in the urinary system increases the white blood cell numbers in the urine.

pyuria bottle

Pyuria Without Bacteriuria

Bacterial infection is not the only cause of pyuria. There are other causes which are enumerated below. Without bacterial invasion, pyuria can be asymptomatic. The cause is difficult to detect when pyuria is not caused by a bacterial invasion, hence diagnosis and treatment may be deemed more difficult because the physician will have to “explore” as to what would stop or eliminate this high number of WBCs in the urine. In cases like this, tuberculosis, kidney diseases, cancer, or even drugs are being suspected as the possible causes.

The elderly group is prone to asymptomatic pyuria, primarily because urinary incontinence may be inevitable as we grow old. Our muscular system tends to grow old too as our age do. As people age, the muscles, including the smooth muscles in our urinary system, become weak and less efficient, thus old people become incontinent. Because of this, some prefer to use indwelling catheters for a long time, which predisposes them to infection. Almost fifty percent of people who use indwelling catheters for a long period of time become victims of asymptomatic pyuria. However, asymptomatic pyuria can be self-limiting, meaning it goes away on its own, even without treatment.

Differences Between Pyuria and Bacteriuria

Pyuria is the presence of white blood cells (>10 WBCs per high power field) which causes pus sufficient enough to produce cloudy or milky urine. Whereas, bacteriuria is defined as the presence of >1 × 105 CFU/mL bacteria in two consecutive samples of urine.

In pyuria, the presence of WBCs or pus cells signify that there is an inflammation going on inside our body, particularly in the genitourinary tract. WBCs act as the soldiers of our body, attacking foreign organisms that are deemed harmful. As this natural defense mechanism takes place, the epithelial linings are also being affected because of too much “soldiers”, thereby causing inflammation. Hence, this high amount of WBCs or pus cells is reflected in our urine.

Bacteriuria is the presence of bacteria in the urine. Typically, urine has a small amount of bacteria. This is normal since our genitourinary tract is moist from the inside and out. Remember the principle “moisture attracts microorganisms”? This is applicable to this case. But this brings no harm to us. However, in large amounts, bacteria can bring about infection, commonly urinary tract infection. Bacteriuria can either be symptomatic or asymptomatic. Symptomatic bacteriuria can be treated with antibiotic therapy. The asymptomatic type is self-limiting, meaning it goes away on its own without any treatment.

Pyuria Risks

Urinary tract infection or UTI is most likely to lead a patient to having pyuria. Asymptomatic pyuria is a result of chronic urinary incontinence or chronic use of indwelling catheter.

Incidence and Prevalence

Urinary tract infection (UTI) is the most common cause of pyuria. Below 50 years of age, UTI is mostly common in females as compared to males. This is because the urethra of females is shorter than the urethra of males, thus, bacteria can progress into the upper urinary system easily. Furthermore, the vagina and urethral areas are more prone to bacterial invasion due to its proximity to the anus. The prevalence for both sexes increases when the individual reaches 50 years of age. By this time, the female-male ratio decreases as men become exposed to prostate diseases.

Symptoms of Pyuria

  • Cloudy or milky urine
  • Foul-smelling urine
  • Frequent urgent need to urinate
  • Discomfort on urinating
  • Fever

Pyuria Causes

  • Urinary Tract Infection (UTI)
  • Cystitis or bladder infection
  • Sexually transmitted infectious disease: Chlamydia, Gonorrhea
  • Infection of the prostate
  • Viral infections: Herpes Simplex and Human Papilloma Virus (condyloma or warts)
  • Other infections: tuberculosis, anaerobic bacteria (microorganisms that live better in an environment with little or no oxygen), actinomycosis (a.k.a. lumpy jaw), fungal infections
  • Parasites: Trichomona vaginalis, Schistosoma haematobium, Giardia lamblia, and Entamoeba histolytica
  • Inflammatory lesions of the kidneys: lupus nephritis, polyarteritis nodosa, analgesic nephropathy, glomerulonephritis, lead nephropathy, secondary syphilis
  • Glucocorticoid medications
  • Benign or malignant tumors in the urinary system
  • Stones of the kidney, ureter or bladder
  • Mechanical trauma
  • Pregnancy
  • Other considerations: Reiter’s syndrome, contamination of vagina, retroperitoneal fibrosis, chemicals such as soap or medication in the urethra or bladder

Pyuria in Pregnancy

Healthy or not, a pregnant woman is at an increased risk for UTI and bacteriuria, which may later progress to pyuria, compared to nonpregnant women. This is because of the significant hormonal changes that occurs during pregnancy. This sudden change predisposes the pregnant woman’s body to infection particularly in the genitourinary tract because urinary stasis and ureteral reflux may happen frequently. This allows the bacteria to accumulate which will lead to infection. Moreover, a woman’s urethra is shorter as compared to males. This allows the bacteria to advance further into the upper urinary system.

Whether it be pyuria, UTI, or bacteriuria, symptomatic or not, proper treatment is most deserved by the pregnant mother, not just for her own sake but for the sake of the baby. We don’t want any complications on the baby’s part just because we were not able to manage a simple condition. Furthermore, prevention is better than cure right? So below is a table of oral antibiotics for pregnant women with asymptomatic bacteriuria. If you’re a pregnant woman suffering from pyuria, please take note that your doctor’s prescription is still the best for you. This table below is for informative use only.


  • History: Pyuria can be acquired even without symptoms. However, an individual may seek medical attention when he/she notices cloudy or milky urine while having a discomfort upon urination with increased urinary frequency.
  • Physical exam: Physical check up alone will not determine presence of pus cells in the urine. It must always be supported with laboratory exams. However, if a suspected individual has already kidney malfunction, expect cases of fever, tenderness, and kidney enlargement.
  • Tests: The test for pyuria is plain urinalysis. The findings actually are the initial determinants if a patient is suspected of pyuria (even without the presence of symptoms). To support further, culture of urine will be conducted to determine the strain of bacteria that caused the pyuria. Negative urine culture result means the patient is clear from this condition. Intravenous pyelogram (a contrast study) or ultrasound imaging of the kidneys may be performed in order to identify kidney abnormalities or infection.

Treatment for Pyuria

Sterile pyuria, or asymptomatic pyuria in the absence of infection, does not really require treatment. Individuals with UTI undergo antibiotic therapy. If there will be no response after series of medication, further evaluation is recommended to target the proper treatment needed.


  • Norfloxacin (Noroxin)
  • Ampicillin (Principen)
  • Minocycline (Minocin)
  • Levofloxacin (Levaquin)
  • Ciprofloxacin (Cipro)
  • Amoxicillin (Augmentin)
  • Doxycycline (Adoxa)

Prognosis of Pyuria

The exact cause of pyuria must be determined to come up with an accurate prognosis. Generally, asymptomatic pyuria disappears spontaneously. Some may remain without causing problems. (But who would want to have a pus on their urine?!) UTI often clears in no time when treated with appropriate antibiotics. It can be alleviated without antibiotic but in a slow pace, and recurrence and/or complications are more likely.

Pyuria Complications

Probable complications depend on the gravity of the condition. If there is bladder infection, there may be an advancement of the infection to the upper urinary tract which houses the ureters and the kidneys. For individuals with kidney infection, sepsis (generalized infection) and kidney damage can result due to the widespread infection.

Prevention of Pyuria

  • Good personal hygiene is the key to prevent urinary tract infections, hence pyuria. After urination or defecation, wipe the vaginal and anal area from front to back. There are more microorganisms found in the anal area. Wiping from front to back minimizes the chance of spreading these microorganisms to the vaginal and urethral areas.
  • Wash or shower before and after having a sexual intercourse. This lessens the chance of having honeymoon’s cystitis, hence pyuria.
  • For those who require the use of indwelling catheters, observe sterile technique while performing the procedure.
  • Drink plentiful of water. This helps to flush the bacteria out of our urinary system as it dilutes our urine.




  1. I have leucocyte esterase +++ in my urine. I am a chronic kidney failure patient on dialysis.

    I have taken two doses of Zinat 500mg 3 times a day, together with interflora 250mg 2/daily and Fluzol.

    This infection has been in my urine for 3 months after extensive treatment.

    I am due for a kidney transplant and need to eradicate the pyuria.

    Your comment is greatly appreciated.

  2. I have pyuria and it keeps coming back. The first time I got pyuria it was caused by a UTI. But why do I keep getting it and how can i permanently cure pyuria?


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