What to know about lower glucose readings in a typical healthy individual
It’s actually not abnormal for people’s glucose to intermittently dip below 70mg/dl. In one study of healthy individuals wearing CGM, 41% of people experienced glucose levels less than 70 mg/dL in a 24-hour period. If you feel unwell or symptomatic, seek medical attention.
What can cause low glucose readings?
Post-meal lows: Glucose dips below 70 mg/dL that occur just after a post-meal glucose spike may indicate reactive hypoglycemia; which is an exaggerated insulin response to a high carbohydrate meal, causing an overshoot in the amount of glucose that is absorbed out of the bloodstream and into cells, leading to a dip in glucose after a meal. These glucose dips can be characterized by symptoms including fatigue and lack of energy, and can be avoided by a low-carbohydrate/low-glycemic eating pattern with reduced post-meal glucose spikes.
Nighttime lows: Research also shows that glucose levels decrease by an average of 5% during REM sleep, as compared to non-REM sleep stages, which may contribute to periodic dips seen at night in nondiabetic people. Additionally, pressure on the CGM sensor from laying on it can cause the sensor to register low values. Feel free to check a finger stick glucose to confirm. If you feel unwell or symptomatic, seek medical attention. If you feel well, it is unlikely something you should worry about.
Sensor calibrated too low (first 36 hours of use): It can take time for the sensor to calibrate accurately, which may be why you’re seeing low values. Wait until the sensor has been in place for 36 hours to see if it levels out into a normal range.
Sensor error: Sustained extremely low levels for more than 30 minutes may indicate sensor malfunction. You can check a fingerstick glucose level to confirm. If you feel unwell or symptomatic, seek medical attention.
Read more on the Levels blog here: Why do my glucose levels go low during my sleep?