When should I calibrate my CGM, and when should I not?

Quick Answer

Calibration Basics for CGM: When It Applies and When It Does Not is usually a signal-interpretation problem more than a raw device problem.

Mechanism and Interpretation

The literature on CGM performance repeatedly highlights that lag and local tissue factors can produce transient mismatch, especially during rapid rise/fall windows. Compression artifacts at night are well described and can look dramatic despite low physiologic plausibility.

Clinical interpretation quality improves when users combine absolute values with rate-of-change and timing context. This prevents overreaction to short-lived anomalies and supports safer decision pacing.

Practical Fix Sequence

Use a stepwise correction sequence: identify pattern class, verify recurrence, then adjust one variable at a time. Random multi-variable changes make it harder to identify true causality and often increase frustration.

For persistent issues, align troubleshooting with formal labeling and care-team guidance. A reproducible logging approach is often more helpful than adding more ad hoc checks.

Clinical Caveats

Single outlier readings are rarely enough for strategy change. Clinical interpretation should prioritize repeated patterns, symptom concordance, and timing context before changing therapy logic.

Action Checklist

Use this short checklist as your implementation layer so evidence can be translated into consistent daily decisions.

Tag events by context (sleep pressure, meal timing, activity, first-day wear).
Review trend direction and persistence before reacting to a single value.
Use confirmatory checks when symptoms and CGM readings diverge in high-risk moments.

References

Medical Disclaimer

This content is for informational purposes only and does not constitute medical advice. Always consult your healthcare provider before making decisions about your diabetes management or CGM device selection.