How do I stop CGM compression lows when sleeping on my side?

Hey Mark, this is easily one of the most frustrating parts of wearing a Continuous Glucose Monitor! A "compression low" happens when you put physical weight on your sensor by laying directly on it. The pressure temporarily restricts the flow of interstitial fluid around the tiny sensor wire, making the device think your blood sugar is tanking, even when your actual levels are perfectly fine.

If you don't want to force yourself to become a back-sleeper, the best fix is strategic sensor placement. Most manufacturer manuals suggest the back of the upper arm, but for side sleepers, that is exactly where the body weight hits the bed. Next time you apply a sensor, try adjusting the placement slightly off the center line. Many side sleepers find success by applying the sensor slightly toward the front of the bicep, or tucked closer to the armpit. The goal is to find that natural "pocket" on your arm that doesn't make direct contact with your mattress.

If changing the site isn't working, you can try altering the pressure point. Some people arrange a firm pillow to prop their arm up so the sensor hovers off the bed. Others use a hollow elbow pad worn directly over the sensor to bear the weight, or grab a 3D-printed CGM shield off Etsy designed specifically to prevent pressure from resting directly on the transmitter.

When that dreaded alarm does wake you up, simply rolling over relieves the pressure, and the false reading will usually bounce back to normal within 10 to 15 minutes. Just remember, if you ever feel "off" or aren't entirely sure it's a fake alarm, always verify with a quick fingerstick to be safe!