Flash Glucose Monitoring(FGM)
Definition
A type of glucose monitoring that stores continuous glucose data on the sensor but requires the user to scan the sensor with a smartphone or dedicated reader to view the current reading and recent trend data. The FreeStyle Libre 2 is the primary example of flash glucose monitoring. Unlike real-time CGMs, flash monitors do not automatically push alerts for high or low glucose events unless actively scanned, though newer models like the Libre 3 have transitioned to full real-time monitoring.
Why “Flash Glucose Monitoring” Matters for Glucose Monitoring
Understanding flash glucose monitoring is essential for anyone using or evaluating a continuous glucose monitor. This concept directly affects how CGM devices are designed, how glucose data is interpreted, and how clinical decisions about blood sugar management are made. The technical foundations of CGM technology determine the accuracy, reliability, and user experience of every device on the market — from the Dexcom G7 to over-the-counter options like the Abbott Lingo.
This term is particularly relevant to 2 CGM products in our database. Understanding FGM helps you compare devices more effectively and choose the right continuous glucose monitor for your specific needs.
Related Terms
A wearable medical device that tracks glucose levels in interstitial fluid 24 hours a day through a tiny sensor inserted just under the skin.
A continuous glucose monitor that automatically and continuously transmits glucose readings to a display device — such as a smartphone, smartwatch, or insulin pump — without requiring the user to scan or interact with the sensor.
The reusable electronic component that attaches to a CGM sensor and wirelessly sends glucose data to a smartphone, smartwatch, or dedicated receiver via Bluetooth.