Pyuria: Symptoms, Diagnosis & Treatment

Pyuria is a medical term used to describe the presence of pus in the urine, caused by an increase in white blood cells called leukocytes. While a small number of leukocytes in the urine can be normal, higher levels may indicate an infection, kidney problem, or autoimmune disorder.

This condition is usually detected through a urine microscopy test, commonly performed as part of a urinalysis (UA). Pyuria is diagnosed when the urine contains more than five leukocytes per microscopic field or over 20,000 leukocytes per mL.

Identifying the cause of pyuria is essential for proper treatment. Depending on the underlying cause, a healthcare provider may prescribe antibiotics, anti-inflammatory medications, or corticosteroids to reduce inflammation and treat infection.

Main symptoms

The two main signs of pyuria are:

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

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

• Pain and discomfort when urinating;
• Burning with urination;
• 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 healthcare provider for 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 urinalysis (UA), which includes both macroscopic and microscopic examination of the urine. 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. A 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 presents with UTI symptoms, the doctor may prescribe antibiotics.

Autoimmune-related causes may require treatment with immunosuppressants. Regardless, urine with a milky or white appearance should be assessed by a healthcare provider.