Dexcom tips

Reminders for Your Dexcom Trial Wee


The Dexcom system will only be able to provide meaningful feedback about your blood sugar trends if the receiver is properly calibrated.

  • You will first be prompted to calibrate the device two hours after your sensor is inserted. You can view the progress of this “pre-heat” phase by watching the small green pie fill up at the top right corner of the screen. When you see two large blood drops on your receiver screen, it is time for your first calibration.

  • Two blood drops means the Dexcom is requesting TWO separate blood tests from TWO separate test strips using your regular blood sugar meter. It is important that you enter these starter readings at a time when your blood sugar is stable. In other words, if you have eaten, exercised, given insulin, etc. in the last two hours, it is better to wait until you are outside of this window. Entering two readings when your blood sugar is moving either up or down will result in less accurate readings.

  • After this initial calibration, you will be prompted to enter only one reading (use one test strip) every 12 hours for the remainder of your week-long trial. The same rules should apply to this. Again, it is better to wait and calibrate your Dexcom later than 12 hours rather than enter a reading at a time when your blood sugar is changing just because you have been prompted by the screen to do so.

  • We do not recommend entering more than 2 readings per day, as this can also interfere with the accuracy of the receiver.

Other Important Reminders

  • The transmitter is completely waterproof and can be worn without additional protection in the pool, shower, etc.

  • The receiver must be within 20 feet of you in order to continuously track your blood sugars.

  • The device will be less accurate if you are taking acetaminophen (ibuprofen should not affect it).

  • For patients on insulin: Most patients are not used to seeing their blood sugars constantly and, therefore, are not aware of how high their numbers may rise after meals. DO NOT OVER-CORRECT. If you have been instructed by your doctor to correct your blood sugar two hours after meals, continue to do so but do not give more insulin within the two hour window. This is called insulin stacking and can significantly increase your risk for low blood sugars (hypoglycemia).