Learning essentials

Learning essentials

How to read a laboratory report

Understand the labels before focusing on the flags.

Updated September 17, 2026 · Educational reference

Reference range and units

Use the units and reference interval printed by the performing laboratory. Results from different methods may not be directly comparable.

A flag is a clue

An out-of-range value is not always a disease, and an in-range value does not always rule one out. Interpretation depends on the question, symptoms and other findings.

Plan your follow-up

Ask whether a repeat test, different timing or further evaluation is needed. Do not change prescribed treatment solely because a portal marks a number in red.

Sources & perspective

This is an editorial adaptation of the Purser Wellness Method manuscript, practitioner course and testing education materials. Purser teaching connections are labeled separately from clinical interpretation. Private cases and individual treatment protocols are not reproduced.

Use the public resources below for additional context.

MedlinePlus: understanding laboratory testsNIH: nutrient fact sheets