Urinalysis interpretation
Formal Definition
Urinalysis (UA) — a point-of-care or lab-performed urine test evaluating three components: (1) Macroscopic/dipstick (color, clarity, specific gravity, pH, glucose, ketones, blood, protein, nitrite, leukocyte esterase, urobilinogen, bilirubin), (2) Microscopic (RBCs, WBCs, epithelial cells, casts, bacteria, yeast, crystals), and (3) sometimes culture confirmation; a high-yield, low-cost bedside and lab test that can quickly direct differential for urinary symptoms, identify systemic disease (glucose for diabetes, ketones for DKA, blood for rhabdomyolysis, protein for kidney disease, bilirubin for liver disease, nitrites for UTI), and confirm catheter-associated infections.
How It's Used on the Ward
"UA" or "urinalysis" — ordered for any urinary symptom (dysuria, frequency, flank pain, hematuria), suspected UTI, sepsis workup (UA early helps with source), post-op monitoring, pregnancy workup, kidney-related labs; routinely part of admission order sets especially for elderly or febrile patients in whom UTI is possible cause.
Example
""84-year-old long-term care resident with dementia, admitted with new confusion, low-grade fever (37.8°C), mild leukocytosis (WBC 11.5), and decreased PO intake. Workup: UA ordered. Result: cloudy yellow, pH 7.0, SG 1.020, glucose -, ketones -, blood -, protein trace, nitrite +, leukocyte esterase +++, microscopic >50 WBC/hpf, 5-10 RBC/hpf, many bacteria. Documented: 'UA notable for nitrite+, LE +++, pyuria and bacteriuria consistent with UTI. Urine culture sent; CT no obstructive stone. Empiric ceftriaxone x1, will narrow per sensitivities. Mental status improved with rehydration and antibiotics over 48 hours.'""
Clinical Context
Dipstick interpretation: glucose — diabetes (or pregnancy SGLT2 inhibition); ketones — starvation, DKA, alcoholic ketoacidosis; blood (heme +) — UTI, stone, glomerular disease, menses, rhabdomyolysis (no RBCs on microscopy if myoglobinuria); protein — glomerular disease (need quantification with protein/creatinine ratio or 24h urine); nitrite — gram-negative bacteria (E. coli, Klebsiella, Proteus) convert nitrates to nitrites; LE — detects WBC enzymes, marker for pyuria/UTI. Microscopy: RBCs (consider glomerular vs non-glomerular — dysmorphic vs isomorphic); WBCs (>10/hpf suggests pyuria, often UTI but also sterile pyuria in TB, interstitial nephritis); casts (hyaline = normal/concentrated; granular = ATN; RBC casts = glomerulonephritis; WBC casts = pyelonephritis; muddy brown casts = ATN); bacteria (correlate with culture); yeast (candiduria in catheterized, immunocompromised, broad-spectrum antibiotics). Specimen handling: clean catch midstream preferred; catheterized specimens for catheterized patients; bag collections for toddlers (high contamination). Asymptomatic bacteriuria: common in elderly women, catheterized patients; do NOT treat — only treat symptomatic UTI to avoid C. diff, resistance.