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CGM Basics

How does Dexcom ONE CGM System work?

Last Updated · May 30, 2023

Continuous Glucose Monitoring (CGM) systems track glucose levels throughout the day.

  • An automatic applicator inserts a tiny sensor wire just beneath the skin. An adhesive patch holds the sensor in place. The sensor measures glucose levels in the interstitial fluid all day and night.

  • A small, reusable transmitter connects to the sensor and sends real-time readings wirelessly to your compatible smart device* so you can see your real-time glucose levels and historical trends.

  • The Dexcom ONE app can also be set to send custom alerts to the user when certain glucose thresholds are reached.

*To see a list of compatible smart devices, visit

5-step learning journey

Discover education resources, organised in a 5-step journey, to learn key information about your Dexcom ONE CGM system, from getting started, your first 10 days, to using Dexcom ONE in the long run.

Step 1: The basics of CGM
Step 2: Getting started
Step 3: Your first 10 days
Step 4: Using Dexcom ONE in the long run
Step 5: Understand your Diabetes trends