Pyuria: Symptoms, Causes, Diagnosis & Treatment

Pyuria is the term used to describe pus in the urine, which is measured by the amount of leukocytes in the urine. The presence of some leukocytes in the urine is considered to be normal, however when large amounts that also present with other symptoms may be a sign of an infection, kidney problems or autoimmune disease.

Pyuria is typically identified through a microscopy test, also known as a urine R&M or type 1 urine test. Pyuria is diagnosed when the urine presents with more than five leukocytes per microscopic field, or less than 20,000 leukocytes/mL.

It is important to identify the underlying cause of pyuria, as this will help to guide treatment. The doctor may opt to prescribe antibiotics, anti-inflammatories or corticosteroids depending on the cause.

Main symptoms

The main two signs of pyuria are:

• Urine with a milkier appearance
• Cloudy or non-transparent urine

However, more symptoms may be noted depending on the cause of pyuria, such as:

• Pain and discomfort when urinating
• Burning
• Lower back pain
• Genital itching 
• Reduced urine output
• Feeling of a full and heavy bladder, even after urinating
• Frequent urge to urinate.

Pyuria symptoms are the result of increased leukocytes in the urine. It is important to see a doctor for assessment if you have any of the above symptoms, so that the underlying cause can be diagnosed and treated. 

Common causes

Pyuria can be caused by many health conditions, but is most commonly the result of a UTI or autoimmune disease. Read more about what causes high leukocytes in the urine.

Confirming a diagnosis

Pyuria is mainly detected through a urine R&M test, which looks at the urine through a macro and microscope. The macroscopic analysis evaluates the characteristics of the urine, mainly the color and consistency. Urine may be reported to be whiter or more milky depending on the amount of leukocytes in the urine.

Microscopic analysis looks at the cellular composition of the urine. Pyuria is diagnosed if there are more than 5 leukocytes per field, or more than 20,000 leukocytes per mL of urine. When other microorganisms are identified in the urine in addition to leukocytes, a urine culture may be indicated. The doctor may also opt to order blood tests and a 24-hour urine test.

Treatment options

Treatment for pyuria depends on the underlying cause and whether or not the patient has other symptoms. If the pyuria is due to the presence of foreign microorganisms and the patient does present with symptoms, the doctor may prescribe antibiotics.

Autoimmune-related caused may require treatment with imunosuppressants. Regardless, urine with a milky or white appearance should be assessed by a doctor.