CGM Troubleshooting: Quick Fixes for Diabetes Devices

Continuous glucose monitors (CGMs) are wearable devices that make managing diabetes easier. Popular brands include Abbott’s FreeStyle Libre 3, Dexcom’s G7, Medtronic’s Guardian Connect and Senseonics’ Eversense system. After getting your CGM, troubleshooting may be needed as you adjust and ensure everything works smoothly. Here are some common errors that happen when you wear a CGM and some CGM troubleshooting tips.

Trouble applying the sensor

Every CGM comes with instructions for applying the sensor, but applicators can sometimes malfunction. Maybe the spring popped before you were ready, or the applicator didn’t release the sensor. If this happens:

• Don’t try to reapply or reuse the sensor.
• Save the sensor and its packaging. Manufacturers may need the serial number.
• Contact the manufacturer for a free replacement. Be prepared to return the faulty sensor if requested.
• Here is the customer contact info for the CGMs available:

• • Freestyle Libre
  • Dexcom
  • Medtronic Guardian Connect
  • Senseonic Eversense

Sensor falling off

When you’re new to CGMs, they might feel awkward at first, and accidents happen. Whether it’s during a workout, changing clothes, or just after applying, sensors can get knocked off. To help prevent this:

• Clean the area with an alcohol wipe before applying the sensor.
• Avoid lotions beforehand.
• Use a liquid adhesive for extra stickiness.
• Try different application sites that are less likely to get bumped, but check with your doctor first.
• Avoid exercise or showers right after applying.
• Consider wearing a patch over your sensor to keep it secure. Some brands, like Dexcom, even offer free patches.

Losing signal with your phone

Many CGMs let you monitor your glucose through a mobile app instead of a separate device.

Sometimes, though, you might lose the connection between your phone and the sensor. To fix this:

• Make sure your phone is close enough to receive signals.
• Check for water around the sensor; it could disrupt signals.
• Toggle your phone’s Bluetooth off and back on.
• Avoid applying pressure to the sensor, especially while sleeping.
• Keep your phone charged; low battery mode can disable Bluetooth.

Skin reactions to CGM adhesive

CGMs stick to your skin using adhesives, and some people can have bad reactions to them. If you experience irritation or rashes:

• Rotate where you apply the CGM to avoid overusing the same spot.
• Talk to your doctor about patch testing to identify problematic adhesives.
• Use an adhesive remover when taking off the sensor to protect your skin.
• Apply a liquid adhesive barrier or patch under the sensor to prevent direct contact.

The bottom line

Using a CGM may take some getting used to, but once you’ve mastered the basics, it can make managing diabetes so much easier.

With a little patience and the tips above, you’ll be well on your way to making the most out of your device.

CGMs aren’t just about convenience—they’re powerful tools that can improve your health and quality of life. Keep going—you’ve got this!

This content was made possible by Abbott, a Founding Partner of Beyond Type 1. Beyond Type 1 maintains editorial control over its content.