How to Read Your Lab Results: A Beginner's Guide

Getting your lab results can feel overwhelming. Here's how to make sense of those numbers.

Understanding Reference Ranges

Reference ranges (also called normal ranges) are based on where 95% of a "healthy" population falls. But "normal" doesn't always mean "optimal."

Important Points - Ranges vary between labs - Ranges are based on population averages - Being at the edge of normal may still cause symptoms - Optimal ranges are often narrower

Reading Your Results

Result Columns - Your value - Reference range - Flag (H for high, L for low) - Units of measurement

Flagged Results - **H (High):** Above reference range - **L (Low):** Below reference range - No flag: Within reference range

Common Units

• ng/mL: nanograms per milliliter
• pg/mL: picograms per milliliter
• mIU/mL: milli-international units per milliliter
• mg/dL: milligrams per deciliter
• mcg/dL: micrograms per deciliter

Questions to Ask

• Is this in the optimal range, not just normal?
• How does this compare to my previous results?
• What might be causing abnormal results?
• What should I retest and when?

Tracking Over Time

One result is a snapshot. Tracking trends over time gives you the full picture. Keep copies of all your labs.

References

• Ozarda, Y., et al. (2018). Reference intervals: current status, recent developments and future considerations. *Clinical Chemistry and Laboratory Medicine*, 56(7), 969-981.
• Ceriotti, F., et al. (2009). Common reference intervals for aspartate aminotransferase (AST), alanine aminotransferase (ALT) and gamma-glutamyl transferase (GGT) in serum: results from an IFCC multicenter study. *Clinical Chemistry*, 55(3), 549-555.