Totally wacky readings

Hi. I’ve been a Dexcom user for about a month and have found it to be very reliable overall. But I had a strange experience today and wonder if anyone has had something similar or any thoughts on what might have caused it.

My BG was a bit low (about 65) as I was making lunch, so I took enough glucose to get me up to around 80-something. Ate my very low-carb lunch of turkey, cheese, low-carb bread and clear soup. As I was washing the dishes, my Dexcom beeped. Double up arrows! According to Dex, my BG went from 65 to 150 in about 10 minutes. This didn’t make sense to me, considering what I ate, so I did a fingerstick to confirm. 61! Tried again to be sure. 65. I used that number to calibrate Dex, and since then it has been behaving. But now I don’t know whether to trust it.

Has anyone had this happen? Any thoughts would be welcome.

This has happened to me more than once. My theory is that for some reason the sensitivity of the sensor increased. I calibrate and get on with my life. So far it has happened only once per sensor, typically around day 3, for about 1 out of 10 sensors.

Interesting – I’m on day 3 of this sensor. Trying, as you suggest, to get on with my life and not look at the readout every 2 seconds!

I have had this happen also. If it happens several times within the first seven days, I report it to DexCom as a bad sensor and ask for a replacement. If you have an internet connection, the customer service agents can read the data downloaded from your receiver and see the calibration entries and the values reported by your receiver. Unfortunately, the sensors are not turly uniform in their responses so you have to develop a sense on your own when you feel the sensor is wrong. The answer is simple, just take a finger stick test. That is the gold standard. The good news is that when a sensor is “good” it is consistantly good and tends to get better. However, “bad” sensors tend to remain that way. Do not get anxious about any single sensor. If you have problems with one particular sensor change it and go on.

Thanks everyone. I called the help line and they couldn’t give me an answer, but they’re sending me a replacement sensor.

I use the Ronald Reagan approach - trust and verify. Whether the dex or a finger stick, if something doesn’t seem to make sense it probably isnt true.