How to calibrate G7 Dexcom is a common question for users looking to ensure the most accurate glucose readings. While the Dexcom G7 is designed to be factory-calibrated and does not require manual calibration, some users may experience slight discrepancies in their readings. This can lead to concerns, especially when glucose levels don’t match how you feel.
Take, for example, Belinda from Fort Lauderdale, a longtime Dexcom user who recently upgraded to the G7 model. She noticed that her sensor readings were consistently 10-15 mg/dL higher than her blood glucose meter. Unsure of whether she needed to calibrate her device, she reached out to us at Aptiva Medical for guidance. We helped her understand that while manual calibration is unnecessary, there are several steps she could take to troubleshoot and ensure accuracy.
If you’re experiencing similar concerns, this guide will walk you through how to check and improve the accuracy of your Dexcom G7. You’ll learn what affects sensor readings, when manual comparison is helpful, and how to troubleshoot potential issues.
Does the Dexcom G7 Need Calibration?
Unlike previous Dexcom models, the Dexcom G7 does not require manual calibration because it comes factory-calibrated. This means that when you apply a new sensor, it is already pre-set to provide accurate readings based on its built-in algorithm. Unlike older models like the Dexcom G5, which required daily fingerstick calibrations, the G7 relies on advanced sensor technology for precision.
However, there are times when you may feel like your Dexcom G7 readings are not accurate. While calibration is not an option, there are steps you can take to ensure your sensor is providing reliable data. Understanding when and why discrepancies occur is key to using your Dexcom effectively.
When Might You Need to Check Accuracy?
Although calibrating the Dexcom G7 manually is not required, there are certain scenarios where checking your readings against a blood glucose meter can be useful:
- You have symptoms that don’t match your Dexcom readings. If you feel shaky, dizzy, or fatigued but your sensor says your glucose is normal, double-checking with a meter is a good idea.
- Your sensor is new. It can take up to 24 hours for a new sensor to stabilize. During this period, readings may fluctuate slightly.
- You are experiencing rapid blood sugar changes. The Dexcom G7 measures glucose from interstitial fluid, which can lag behind blood readings, especially when glucose levels are rising or falling quickly.
- Your sensor is placed in an area that moves a lot. If the sensor is on a high-movement area, such as a bony or muscular spot, it may not provide the best readings.
- Your blood glucose meter is showing significantly different numbers. If your meter and Dexcom G7 consistently show differences greater than 20%, it’s worth investigating further.
Understanding when to compare readings can help you make the most of your Dexcom G7 and improve its accuracy when necessary.
Aptiva Medical’s 9-Step Guide on How to Calibrate G7 Dexcom
While the Dexcom G7 does not require manual calibration, you can follow these nine steps to check and improve the accuracy of your readings.
Step 1: Wash Your Hands and Prepare Your Glucose Meter
Before comparing your Dexcom G7 readings with a fingerstick blood glucose test, always wash your hands thoroughly with soap and water. Even small traces of food, lotion, or dirt can interfere with the accuracy of your blood glucose meter reading.
If soap and water are unavailable, you can use an alcohol swab, but let your finger dry completely before testing. Avoid testing if your hands are wet, as moisture can dilute the blood sample and give an inaccurate result.
Step 2: Take a Fingerstick Reading
Using a high-quality, FDA-approved blood glucose meter, check your blood sugar level. Always follow the manufacturer’s instructions and ensure the test strips are not expired.
To get the most accurate result:
- Use a fresh lancet to avoid contamination.
- Prick the side of your fingertip (not the center) for a more accurate blood sample.
- Wipe away the first drop of blood and use the second drop for testing.
These small details can make a big difference in getting the most reliable blood glucose meter reading.
Step 3: Compare Your Dexcom G7 Reading
Once you have your blood glucose meter reading, immediately check your Dexcom G7 app or receiver to compare the two values. Since the Dexcom G7 updates every five minutes, try to compare both readings at the same time to get a more accurate match.
Step 4: Allow for Sensor Delays
The Dexcom G7 measures glucose from interstitial fluid, which naturally lags behind blood glucose readings by about 5-10 minutes. If you just ate, exercised, or took insulin, your CGM may show a different number than your blood meter.
For example, if your blood sugar is dropping quickly, your CGM may read higher than your meter. Likewise, if your blood sugar is rising rapidly, your CGM may read lower.
Step 5: Check for Large Differences
If your Dexcom G7 reading is within 20% of your fingerstick test, it is considered accurate. However, if the difference is greater than:
- 20% for glucose levels above 80 mg/dL
- 20 mg/dL for glucose levels below 80 mg/dL
You may need to investigate further.
Step 6: Consider a Sensor Restart
If your sensor has been in use for a while and suddenly starts showing inconsistent readings, try restarting it. To do this, stop the sensor from the Dexcom G7 app or receiver, then start a new session. This process helps reset the sensor’s algorithm and can improve accuracy.
Step 7: Verify Sensor Placement
Ensure your Dexcom G7 sensor is placed correctly in a low-movement, fatty area, such as:
- Back of the upper arm (recommended by Dexcom)
- Lower abdomen (for some users, though not officially recommended)
Avoid areas that:
- Have scar tissue
- Experience frequent pressure or movement
- Are too close to bones or muscle
Proper sensor placement can make a big difference in how accurate your readings are.
Step 8: Replace the Sensor if Necessary
If you have tried troubleshooting but continue seeing major inaccuracies, the sensor may be faulty. Dexcom offers free replacements for defective sensors. Contact Dexcom Customer Support for a replacement sensor if necessary.
Step 9: Contact Your Healthcare Provider
If your Dexcom G7 readings remain inaccurate after troubleshooting, reach out to your doctor or diabetes educator. They can help determine if:
- Your body is reacting differently to the sensor
- You need a different CGM model
- There’s an underlying health condition affecting your readings
How Can Aptiva Medical Help You?
At Aptiva Medical, we specialize in providing the best diabetes management solutions to help you achieve better glucose control. If you need help ordering your Dexcom G7 CGM, troubleshooting issues, or understanding your insurance coverage, we’re here for you.
Visit us at: 5249 NW 33rd Ave, Fort Lauderdale, FL 33309
Call us at: (800) 310-2568
We offer fast shipping, expert support, and insurance assistance to ensure you get the supplies you need. Contact Aptiva Medical today for personalized diabetes care!
Frequently Asked Questions
Can medications affect Dexcom G7 readings?
Yes, certain medications, such as acetaminophen (paracetamol), may interfere with Dexcom G7 sensor readings, potentially causing inaccuracies. It’s essential to consult your healthcare provider about any medications you’re taking and their possible effects on CGM accuracy.
Is it possible to extend the Dexcom G7 sensor beyond its intended use?
While some users attempt to extend sensor use beyond the recommended 10-day period, Dexcom advises against this practice. Using the sensor longer than intended may lead to decreased accuracy and is not supported by the manufacturer.
How does hydration impact Dexcom G7 sensor performance?
Proper hydration is crucial for accurate sensor readings, as dehydration can affect glucose levels in interstitial fluid, potentially leading to discrepancies between sensor readings and actual blood glucose levels.
Can I wear the Dexcom G7 sensor during activities like swimming or showering?
Yes, the Dexcom G7 sensor is water-resistant and can be worn during activities like swimming or showering. However, it’s recommended to limit exposure to water to no more than 30 minutes at a depth of up to 8 feet to maintain sensor adhesion and performance
