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Using Dexcom ONE in the Long Run

What should I do if my sensor reading and blood glucose value don’t match?

Last Updated · June 15, 2023

There may be times when your readings temporarily don’t match, but don't panic--they are likely to become closer over time. You may find that this occurs for a few common reasons:

  • The first day of a sensor: Newly inserted Dexcom ONE sensors can register glucose readings that are less consistent with those of a blood glucose meter. Those readings should become more aligned over the first 24 hours of sensor use.
  • Your glucose level quickly changes: If your glucose level quickly changes, it becomes more difficult to compare the values shown on your Dexcom ONE and a blood glucose meter. This is because these two different pieces of technology measure glucose from different sources (blood versus interstitial fluid), and blood glucose changes a little before interstitial fluid glucose. Once your glucose level stabilizes, though, the values should become closer and easier to compare.
  • There is pressure on the sensor: If something is pressing on your Dexcom ONE sensor, it can affect your readings. This discrepancy should be easily resolved once the pressure is relieved.

Watch your Dexcom ONE readings over several hours to help determine the best course of action for you.

However, if your sensor readings do not match your symptoms:

  1. Wash your hands with soap and water
  2. Dry them
  3. Take a fingerstick with your meter

If your meter value matches your symptoms, use it to make treatment decisions.

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