About Low Glucose Readings

It’s not abnormal for glucose to intermittently dip below 70 mg/dL. In one study of healthy individuals wearing a CGM, 41% of people experienced glucose levels below 70 mg/dL in a 24-hour period.

Reasons you might be seeing low readings

• Calibration period: If you notice low glucose levels within the first 48 hours of applying your sensor, it may be going through its calibration period. See: Calibration Period: The First 24-48 Hours of Your Sensor.
• Nighttime dips: It’s natural for blood glucose levels to drop during sleep when energy requirements are lower, especially during REM sleep. Pressure on the sensor while sleeping can also create false low readings. Learn more: Why do my glucose levels go low during sleep?
• Post-meal lows: Glucose dips below 70 mg/dL that occur after a post-meal spike may indicate a reactive hypoglycemic response. This is an exaggerated insulin response to a high-carbohydrate meal that can cause glucose to drop rapidly.
• When glucose is actively changing: CGMs estimate blood glucose using glucose in the interstitial fluid (the fluid between skin cells). Readings can lag behind blood glucose by about 15 minutes, especially when glucose is changing quickly (after a meal or workout). If you are comparing readings, it is best to compare when glucose is stable, in a fasted state or 2 to 3 hours after a meal.
• Accuracy margin: The gold standard for accuracy is a blood draw. All at-home glucose monitors have error margins to that standard.
• Location: The best location can vary, but we generally recommend the fleshier part on the back of your arm, in the area between the triceps and shoulder muscle. Placement over muscle can lead to higher failure rates.

Sensor errors can happen occasionally. If you suspect your sensor isn’t reading correctly, please reach out to the Levels Support team at support@levels.com.