You might see low values for several reasons. Here are some of them:
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.
CGM Accuracy
Remember that a CGM measures interstitial glucose levels, which are different from the blood or finger stick (glucometer) glucose level. As a result, there may be differences up to +/- 20 mg/dL (1.1 mmoL/L) in reflected values from your CGM. This value changes depending on how many days you have been wearing the sensor.
There can also be differences from sensor to sensor or the location on your arm.
Learn more about understanding your glucose measurements here.
Fasting
During periods of caloric restriction, including time-restricted eating (TRE) or intermittent fasting, your body’s glucose stores are depleted over time. 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.
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.
Post-meal lows
Glucose may drop below your baseline after a post-meal glucose rise - something called reactive hypoglycemia. This may occur when you eat a high carbohydrate load or high glycemic food, which 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 this may be the result of a faulty sensor, please reach out to our team via in-app chat or care@veri.co.
If you also 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 you should not use it to self-diagnose diabetes or hypoglycemia.