CGM Troubleshooting: False Lows & Highs on Dexcom & Libre

CGM Accuracy: How to Troubleshoot False Lows and Highs on Your Dexcom or Libre

Picture this: you're out for a morning jog, feeling great, when suddenly your CGM alarm blares, warning of a dangerously low blood sugar. Panic sets in. You pull over, fumbling for your glucose meter, only to discover your levels are perfectly normal. Sound familiar? False lows and highs are a frustrating reality for many continuous glucose monitor (CGM) users, impacting glucose management and daily life. But don't worry – we've got your back! This blog post will equip you with practical tips to troubleshoot these inaccuracies on your Dexcom or Libre device, so you can regain confidence in your CGM data and keep your blood sugar management on track.

Decoding Your CGM: How It Works and What Can Go Wrong

Before diving into troubleshooting, let's understand the basics of CGM technology. Continuous glucose monitors work by measuring glucose levels in the interstitial fluid – the fluid surrounding your cells – not directly in your bloodstream. A tiny sensor inserted under your skin measures glucose in this fluid, transmitting the data wirelessly to your receiver or smartphone. Several factors can influence CGM accuracy:

• Hydration: Dehydration can affect interstitial fluid glucose levels, leading to inaccurate readings. Staying properly hydrated is key for optimal CGM performance.

• Temperature: Extreme temperatures can also impact CGM accuracy.

• Sensor Placement: Proper sensor insertion and placement are essential for reliable readings. Consult your device's instructions for detailed guidance.

Troubleshooting CGM False Lows: Reclaiming Your Peace of Mind

A sudden, unexpected low reading can be alarming. Here's how to troubleshoot:

• Double-Check with a Finger Stick: Always confirm a low CGM reading with a finger stick meter. This is the gold standard for glucose measurement and ensures you're making treatment decisions based on accurate information.

• Inspect Your Sensor: Ensure the sensor is properly inserted and hasn't been dislodged. Refer to your CGM's user manual for specific instructions.

• Hydration Check: Dehydration can sometimes mimic low glucose levels on a CGM. If you suspect dehydration, rehydrate and see if the reading corrects itself.

• Compression Lows: Certain activities, like sleeping on your sensor or wearing tight clothing, can cause compression lows. Be mindful of these factors and adjust your habits as needed.

An article by the University of Michigan writes that compression of the sensor site can lead to artificially low CGM readings, especially during sleep. Being aware of this phenomenon can help you differentiate between true hypoglycemia and false lows.

Troubleshooting CGM False Highs: Separating Fact from Fiction

False highs, while less immediately alarming than lows, can still lead to unnecessary insulin doses and disrupt your diabetes management. Here's what to do:

• Finger Stick Verification: As with lows, confirm any unexpectedly high reading with a finger stick meter before taking action.

• Calibration (if applicable): Some older CGM models require calibration. If your device does, ensure it's calibrated correctly according to the manufacturer's instructions.

• Medications and Food: Certain medications and foods can interfere with CGM readings. Consult your healthcare provider to determine if this could be a factor.

• Illness or Stress: Both illness and stress can elevate blood sugar levels, potentially leading to higher CGM readings. Consider these factors when interpreting your data.

Research published by the National Library of Medicine found that factors like aspirin and acetaminophen (Tylenol) consumption can cause falsely elevated CGM readings in some devices. Being aware of these potential interactions can help you interpret your data more accurately.

When to Seek Professional Advice: Knowing Your Limits

While troubleshooting can resolve many CGM inaccuracies, some situations warrant professional medical advice. Consult your doctor if you:

• Consistently experience inaccurate readings

• Suspect a device malfunction

• Have concerns about your CGM's performance

An article by American Medical Compliance emphasized the importance of proper training and ongoing support for CGM users to maximize the benefits of these devices. Don't hesitate to reach out to your healthcare team for guidance.

Key Takeaways: Taking Control of Your CGM Data

• Always confirm lows and highs with a finger stick.

• Proper sensor insertion and hydration are crucial.

• Be aware of factors like compression lows and medication interactions.

• Consult your CGM's user manual and your healthcare provider when needed.

By understanding how your CGM works and following these troubleshooting tips, you can confidently navigate false readings, optimize your diabetes management, and live your life to the fullest. Remember, your CGM is a powerful tool, but it's just one part of your diabetes management toolkit. Trust your instincts, stay informed, and keep communicating with your healthcare team. For more insights on integrating your CGM data with other health metrics, check out GlucoSense's Guide to Tracking Blood Sugars. With the right knowledge and tools, you'll be well-equipped to tackle any CGM challenge that comes your way!