What should you know about a urine drug test sent to a lab?

The laboratory uses an identified sample and a defined testing method to look for requested medicines, drugs or metabolites. The request may be for prescribed treatment monitoring, a safety assessment, or investigation of an unexpected result. Testing is limited to the substances included in the requested panel.

A positive finding means the laboratory detected a target substance or metabolite at the method's reporting threshold; it does not automatically explain when it was taken, why it is present, or how a person feels. A negative result means the requested target was not detected under that test's conditions, not that every substance is absent.

Prescription medicines, over-the-counter products, supplements, sample dilution, timing and laboratory cut-offs can affect interpretation. The clinician should compare the report with your medication list, the reason for testing and any screening result.

Give the testing clinician a complete list of prescribed medicines, pharmacy products, supplements and recently used substances. Do not alter a prescribed medicine to change a result. Ask how your sample was identified, which substances were included, and whether a confirmatory method was used.

If the result has consequences for treatment, work, driving or another formal process, ask who will explain it and how you can correct an inaccurate medication history. A laboratory report should be discussed with the responsible clinician rather than read in isolation.

Seek urgent help for severe sleepiness, slowed or difficult breathing, collapse, seizure, chest pain, severe agitation or confusion after taking a substance or medicine. Bring packaging or a medication list if it is safe to do so. These symptoms need immediate assessment regardless of a pending laboratory report.

Which targets were included in the panel? Is this a screening or confirmatory result? Could any prescribed or non-prescription product explain the finding? What will happen next, and who can discuss a disputed result with me?