Urinalysis
Urine dipstick
The urine dipstick is a multi-parameter reagent strip that screens a single urine sample for several markers at once, including leukocyte esterase, nitrite, protein, blood, glucose, ketones, bilirubin, urobilinogen, pH and specific gravity. It is one of the most widely used near-patient tests in primary care, urgent care and ward settings because it is quick, low cost and needs minimal training.
Why it is measured
It offers a rapid first-line screen for urinary tract infection, kidney disease, diabetes and other conditions, helping clinicians decide whether further laboratory testing such as microscopy, culture or quantitative chemistry is warranted. Because it is semi-quantitative and prone to interferences, it is best used to rule conditions in or out rather than to confirm a diagnosis on its own.
| Typical range | In healthy adults most pads read negative or normal: leukocyte esterase negative, nitrite negative, protein negative (broadly equivalent to under 30 mg/dL), glucose negative, ketones negative, blood negative and bilirubin negative. Urobilinogen is typically around 0.2 to 1.0 mg/dL (approximately up to 17 micromol/L), pH commonly 5.0 to 7.0 (strips cover about 5.0 to 8.5) and specific gravity about 1.003 to 1.030. Results are reported semi-quantitatively as negative, trace, 1+, 2+ or 3+, and the exact thresholds vary by manufacturer, strip lot and reader, so local method ranges should always be used. |
|---|---|
| Sample | Fresh midstream or random voided urine in a clean container, mixed and tested promptly (ideally within about 1 to 2 hours, or refrigerated and rewarmed) to avoid changes in pH, nitrite, glucose and cellular elements. |
| Turnaround | About 1 to 2 minutes per strip. Automated readers typically report in around 60 seconds; a manual visual read requires careful timing of each pad against the colour chart. |
Point of care devices that report it
- Siemens CLINITEK Status+ analyser (reads Multistix and similar Siemens strips)
- Roche Urisys 1100 analyser (reads Combur-Test strips)
- ARKRAY AUTION ELEVEN AE-4020 and AE-4022 (read AUTION Sticks)
- ACON Mission Urinalysis Reader (reads Mission urine reagent strips)
- Manual visual reading of reagent strips against the manufacturer colour chart
Questions, answered
What does a trace or 1+ result actually mean?
Dipstick pads are read semi-quantitatively, so trace, 1+, 2+ and 3+ describe increasing colour change rather than a precise concentration. A trace result can be of borderline significance and many laboratories suggest repeating on a fresh sample, while stronger or repeated positives are more likely to be clinically meaningful. Interpretation should always be made alongside the clinical picture and confirmatory testing where appropriate.
Why does the sample need to be fresh, and what causes false results?
Urine that stands too long can lose nitrite and glucose and shift in pH, and bacterial overgrowth or contamination can alter several pads, so prompt testing or correct refrigeration matters. Common interferences include high-dose vitamin C, which can mask blood and glucose, very dilute or concentrated samples affecting protein and specific gravity, and certain drugs or dyes affecting colour. Following the strip timing and storage instructions reduces these errors.
Can a dipstick replace urine microscopy and culture?
No. The dipstick is a screening tool: for suspected urinary tract infection a positive nitrite or leukocyte result usually prompts laboratory culture for confirmation and antibiotic sensitivities, and a positive protein or blood result often needs quantitative or microscopic follow-up. It is valuable for triage and rapid decision making but is not a stand-alone confirmatory test.