Understanding Your CGM Readings
CGM systems measure glucose in interstitial fluid and display readings over time. Looking at the current value together with the trend can provide more context than viewing a single number alone.
What you may see
Depending on your CGM system, the app or reader may show a current glucose reading, a trend arrow or graph, high or low alerts, and historical glucose information. Features differ by product.
Why readings can differ
CGM readings and blood glucose meter readings are obtained in different ways and may not always match exactly. Changes in glucose can also appear at slightly different times. Sensor performance, application site, pressure on a sensor and other factors can affect readings.
When a reading seems unexpected
Follow the instructions supplied with your CGM. If your symptoms or how you feel do not match the displayed reading, use the confirmation method recommended by the manufacturer and seek appropriate medical advice when necessary.
Alerts and settings
Alert availability and settings vary between products. Review the manufacturer’s instructions before changing settings, particularly where an alert setting forms part of your diabetes management plan.
Important: This page explains CGM information in general terms. It does not provide diagnosis, treatment recommendations, glucose targets or personalised medical advice.