pyuria is a urinary finding characterized by increased white blood cells and inflammatory material in urine, often visible as cloudiness or microscopic leukocytes beyond normal thresholds and commonly associated with urinary tract infection or sterile inflammation of the urinary tract. It is distinguished from hematuria (blood in urine) and proteinuria (excess protein in urine) by its predominance of leukocytes and pus-like material rather than red blood cells or protein alone. Mechanistically, pyuria results from migration of neutrophils and other inflammatory cells into urine in response to infection, stones, obstruction, or inflammatory bladder or kidney disease, and may occur with positive or negative urine cultures depending on whether bacteria are present or the process is sterile. Clinically relevant forms include pyuria associated with uncomplicated lower urinary tract infection, pyuria in the setting of upper tract infection or pyelonephritis, and sterile pyuria seen with conditions such as interstitial nephritis, treated sexually transmitted infections, or inflammatory bladder disorders; when pyuria is the main laboratory finding without a defined diagnosis, it can be captured with abnormal urinary findings such as R82.7 (other abnormal findings in urine). pyuria is sometimes loosely documented as “UTI” based on leukocytes alone; for coding accuracy, documentation should clarify whether pyuria is simply an abnormal finding, a confirmed infection, or part of a broader renal or bladder disease, as these distinctions drive choice between sign codes like R82.7 and specific infection codes.
Refers to purulent material composed of white blood cells, cellular debris, and exudate
[-uria]
Greek ouron (“urine”), via combining form -ouria
Noun-forming suffix meaning “condition of the urine” or “presence of a substance in urine”
The term pyuria combines the root py- (“pus”) with the urinary suffix -uria (“condition of urine”), literally meaning “pus in the urine.” This formation parallels other urine-based terms such as hematuria (“blood in urine”), proteinuria (“protein in urine”), and bacteriuria (“bacteria in urine”), all built on a descriptive root plus -uria to denote abnormal urinary contents. The root py- connects pyuria to related concepts like pyelonephritis (pus and inflammation in the renal pelvis and kidney), empyema (pus in a natural body cavity), and pyoderma (purulent skin infection), underscoring its association with neutrophil-rich exudate. The productive suffix [-uria] is widely used in nephrology and urology to label urine-based abnormalities (for example, glucosuria, ketonuria, myoglobinuria), and in pyuria it specifically anchors leukocyte-rich, purulent urine as a primary laboratory sign.
🔀 ALIASES / ALTERNATE TERMS
Purulent(adjective form — often appears in phrases such as “purulent urine,” “purulent sediment,” or “purulent urinary discharge” in clinical notes describing visible pus in urine)
Pus in urine(lay and clinical term; common in primary care and urgent care documentation when patients describe cloudy or foul-smelling urine suggestive of pyuria)
Leukocyturia(partial/lesser form emphasizing the presence of white blood cells in urine on microscopy; essentially the cellular component of pyuria without necessarily visible pus)
Sterile pyuria(clinical descriptor synonym used when white blood cells are present in urine but routine cultures are negative, seen in settings such as interstitial nephritis, partially treated infection, tuberculosis, or inflammatory bladder disease)
Pyuria with urinary tract infection(related clinical entity phrase describing pyuria as a laboratory feature of UTI; in coding, the infection diagnosis (for example, cystitis or pyelonephritis) is typically primary and pyuria may be captured with R82.7 only if clinically emphasized as a separate abnormal finding)
Pyuria with nephrolithiasis(systemic or syndromic form in which leukocytes and inflammation accompany stones and obstruction; documentation may note “pyuria in the setting of renal colic” as supporting evidence of ureteral irritation or infection)
Microscopic pyuria(etiologic/lesser subtype referring to white blood cells detected only on microscopic urinalysis, without visible macroscopic pus)
Macroscopic pyuria(etiologic subtype describing visibly cloudy or purulent urine, often reported as “frank pus” or “gross pyuria” in severe infection)
Lower tract pyuria(anatomic subtype localized to bladder and urethra, commonly associated with cystitis or urethritis)
Upper tract pyuria(anatomic subtype reflecting renal pelvis and kidney involvement, particularly in pyelonephritis or other upper tract infections)
đź”— RELATED TERMS
hematuria — opposite in terms of primary urinary abnormality compared to pyuria; denotes blood in urine rather than pus, with red blood cells as the dominant abnormal cellular component and distinct diagnostic implications and codes.
bacteriuria — same-root sibling in the sense of describing bacteria in urine; often coexists with pyuria in urinary tract infection, but bacteriuria focuses on organisms, while pyuria focuses on leukocytes and inflammatory exudate.
cystitis — closely related clinical entity involving inflammation and infection of the bladder; pyuria is a common laboratory sign of cystitis, and the bladder diagnosis rather than pyuria alone is usually coded as the principal condition.
pyelonephritis — complex syndrome involving infection and inflammation of the renal pelvis and kidney; pyuria reflects the inflammatory spillover of white blood cells into urine and helps distinguish upper from lower tract disease when combined with systemic symptoms.
Urinary tract infection (UTI) — mechanism term describing infection anywhere along the urinary tract (urethra, bladder, ureters, kidney); pyuria is a core diagnostic feature but should not be coded in place of the specific UTI diagnosis when infection is clearly described.
Leukocyte esterase positive — laboratory mechanism term for dipstick detection of leukocyte esterase, often reported alongside pyuria on microscopy; supports the presence of white blood cells in urine even when cell counts are not fully enumerated.
Inflammatory urinary sediment — cellular mechanism term describing a mix of leukocytes, epithelial cells, and debris in urine, which may be labeled clinically as pyuria when white blood cells predominate.
Other abnormal findings in urine — includes laboratory-detected abnormalities such as pyuria or leukocyturia when no specific urinary tract diagnosis has been established or when pyuria is coded as a secondary sign.
🔧 COMMON CPT CODES (Pyuria-Related Diagnosis & Evaluation)
Urinalysis, automated, with microscopy — automated urinalysis including microscopic evaluation of sediment, used to detect pyuria by visualizing white blood cells and inflammatory debris.
Urinalysis, non-automated, without microscopy — manual urinalysis without sediment examination; may detect leukocyte esterase or gross abnormalities but does not fully characterize pyuria microscopically.
Urinalysis, automated, without microscopy — automated screening of urine chemistry and dipstick parameters, including leukocyte esterase, used to flag potential pyuria before microscopic confirmation.
Susceptibility studies; antimicrobial agent; single method — antimicrobial susceptibility testing performed on urine isolates when pyuria and bacteriuria suggest clinically significant infection requiring tailored therapy.
⚠️ Coding Note: When pyuria is documented as an abnormal laboratory finding without a clearly defined urinary tract diagnosis, R82.7 can be used as a sign code to capture “other abnormal findings in urine,” including leukocyturia or “pus in urine.” If the provider explicitly diagnoses a urinary tract infection, cystitis, or pyelonephritis, those conditions should be coded as the primary diagnoses, and pyuria should be treated as a supporting laboratory feature rather than a standalone principal code. Under-coding can occur when urinalysis reports show “significant pyuria,” “positive leukocyte esterase with WBCs,” or “cloudy urine with pus” but no abnormal urine code or UTI diagnosis is assigned; such phrases may justify adding R82.7 when infection is not definitively diagnosed but the finding is clinically relevant. From an inpatient profee perspective, ensure that evaluation procedures such as urinalysis (81001, 81002, 81003) and urine culture and susceptibility (87086, 87186) are linked to either pyuria sign codes like R82.7 or specific urinary tract diagnoses to demonstrate medical necessity for testing and appropriate follow-up.