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Experiencing lower-than-expected glucose values?
Experiencing lower-than-expected glucose values?

Sometimes your glucose levels will be lower than expected, here's why

Tia avatar
Written by Tia
Updated over a week ago

Shared below are several reasons why you might see low glucose levels on the glucose graph.

1. Calibration Period

In the first 24-48 hours, your CGM sensor is going through a calibration period. During this time, you may find that your glucose readings are less accurate or more erratic than you expect. By day 3, the sensor has completed calibration and should give more accurate readings for the remainder of the sensor lifespan. Read more about this here.

2. CGM Accuracy

Remember that a CGM measures the amount of glucose in your interstitial fluid while a glucometer (aka finger prick device) reads the amount of glucose in your blood. It takes approximately 15-20 minutes for the glucose in your blood to reach your interstital fluid. As a result, there may be value differences of up to +/- 20 mg/dL (1.1 mmoL/L) when comparing readings from the two devices. There can also be general sensor-to-sensor value differences and slight value differences depending on which arm you apply the sensor to. Learn more about understanding your glucose measurements here.

3. Fasting

During periods of caloric restriction, including time-restricted eating (TRE) or intermittent fasting, your body’s glucose stores are depleted. Depending on your starting (or pre-fasting) glycogen levels, the duration and frequency of your fast, and your activity level, your glucose levels may trend downward. During a fast, your body is typically more reliant on fat for fuel as part of the process. Over longer fasts, your glucose requirements decrease as your body switches to other fuel sources.

4. Sleeping

During sleep, our glucose levels lower as our body doesn’t need as much energy, especially during REM sleep. You may also see rapid nighttime drops simply due to pressure on the sensor from lying on your side, in which case the values reflected may be inaccurate and should be interpreted with caution. Here is an article where we explain this further.

5. Post-meal lows

Reactive hypoglycemia occurs when your glucose drops below your baseline after a post-meal glucose rise. This can happen when you eat a high carbohydrate load or high glycemic food because this can lead to your body releasing more insulin than needed.

As a result, more glucose is absorbed than usual and you’ll see a dip in glucose after a meal. Your glucose should return to baseline soon after.

If you believe your sensor is faulty, please contact our team via in-app chat or

If you feel lightheaded or dizzy, you should contact your healthcare provider.

Note that Veri should not be used for medical purposes. The sensor is not a diagnostic tool and should not be used to self-diagnose diabetes or hypoglycemia.

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