Pus in Urine, Key Facts:
- Pus in urine refers to the presence of pus cells in urine analysis.
- Pus in urine may not be visible to the human eye and can only be detected through urine analysis.
- Mild cases of pus in urine are not detectable by the human eye and only seen in urine analysis.
- Normal (clear, yellow) urine does not exclude pus (pyuria).
- Turbid urine doesn’t always mean pus in the urine. The only confirmation of pus in urine is the detection of pus cells in urine analysis.
- Multiple conditions can mimic pus in the urine, such as excess protein, albumin, or lymph fluid in urine, seminal fluid, excess uric acid crystals, and some medications.
- UTI is the most common cause of pus in the urine, especially in women.
- The appearance of pus in urine may vary from small whitish or greyish speckles in urine to completely opaque greyish or beige fluid.
 Normal (clear & yellow) urine.
Pus in urine (pyuria) medical term refers to the presence of pus cells in urine (more than 3 or 5 pus cells per high power field (HPF) in urine analysis.
According to this definition, pus in urine doesn’t necessarily need to be seen by the human eye. It may present only on a microscopic level (reported in urine analysis).
In fact, most patients with pus in urine (pyuria) have normal-looking urine (clear and white.
UTI is the most common cause of pus in urine (especially in women). In such cases, the presence of pus in urine analysis is associated with symptoms of UTI and normal clear, yellow urine.
Symptoms of UTI include:
- Pain during urination (dysuria).
- Frequent going to the bathroom (frequency).
- Sudden urge to pee (urgency).
- Urinary bladder pain (suprapubic pain).
- Foul-smelling urine.
- Some cases may have bloody (pink or reddish) urine.
- Small blood clots in urine.
- A complicated UTI may cause fever, chills, and flank pain.
Normal (clear, yellow) urine does not exclude pus (pyuria). Mild cases of pus in urine are not detectable by the human eye and only seen in urine analysis.
 Cloudy or slightly turbid urine (Whitish or greyish speckles in urine).
Mild to moderate pus in urine may look like small whitish or greyish speckles or tiny white turbidites in urine. Also, the pus may appear as a diffuse mild opacity in urine.
But beware that other conditions may mimic pus in the urine, such as:
- Excess protein or albumin in the urine (albuminuria).
- Excess lymph fluid in urine (Chyluria).
- Seminal fluid, etc.
So, turbid urine doesn’t always mean pus in the urine. The only conformation of pus in urine is the detection of pus cells in urine analysis.
 Turbid urine (yellowish or piece) opaque urine.
The pus in urine may be moderate to severe ins some cases, such as:
- Severe UTI.
- Pus in urine due to obstructive uropathy (by stones).
- Complicated UTI extending to the kidney (pyelonephritis).
In severe cases of pyuria (usually, pus cells >50 cells/HPF, the urine turns into a completely opaque greyish or beige fluid (pure pus).
This look of pus in urine is an indication of a severe condition that may lead to complications such as sepsis (Extension of the infection into the bloodstream and different body organs, a potentially life-threatening condition).
 Greyish debris.
In some cases, pus may also form debris in the bottom of a urine sample that looks whitish or slightly greyish due to the deposition of the thick materials and pus cells.
The remaining urine sample above the debris is typically cloudy.
 Brownish opaque urine (pus+blood) in urine.
In many cases, pus in urine may be accompanied by bloody urine (hematuria). In such a case, the color of urine becomes opaque brown or cloudy-red urine due to the presence of both pus and blood.
Common conditions that cause combined pyuria and hematuria are severe UTI (urinary tract infections) and multiple stones in the urinary tract.
The sample may also contain fragments of blood clots, clumps of pus, or both.
Learn More: 5 Main Causes of blood and pus in urine.
 Other colors of pus in the urine.
Some infections and non-infectious conditions may lead to atypical colors or the appearance of pus in the urine.
For example, green, cloudy urine may be due to a specific and rare type of UTI due to bacteria called pseudomonas aeroginosa.
 BONUS: Mimics of Pus in urine.
Several conditions may look like pus in urine as they cause turbidity (yellowish, whitish, or greyish).
Common Mimics of pus in urine include:
Albumin is a type of protein that circulates in the bloodstream and doesn’t pass through the kidney. Normally, trace amounts of the album are found in urine.
In some diseases affecting the kidney, such as nephrotic syndrome and long-lasting diabetes (diabetic nephropathy), albumin is secreted in large amounts with urine, leading to slightly cloudy and frothy urine.
Chyluria is the presence of lymph fluid in urine. The lymph fluid is a milk-like fluid that is high in white blood cells, protein, and fats.
Chyluria (whitish lymph in the urine) may look like pus) and it occurs due to some rare infections (by a parasite called Wuchereria bancrofti) and other non-infectious causes such as abdominal trauma, renal surgery, and tumors.
- Presence of seminal fluid in urine.
- Excess uric acid crystals.
- Some medications, such as propofol.