I just reported to Dexcom because of major issues with the last sensor and replaced it early. I use the underside and inside of my upper arms and have for a while.
When I pushed the trip hammer to insert the sensor I got pain on a scale of 1 to 10 of 11, and there was a jolt, like a shock, from the sensor site to my wrist. I suppose the inserter needle nicked a nerve.
I was thinking about replacing the new sensor, but the pain subsided and let it go.
Here’s 24 hours of the old sensor.
That reading looks like readings I get when the sensor is failing late in life. For comparison, I had a new sensor hiccup yesterday. This was from a sensor that I installed in the morning, and it had its hiccup about 4 hours after installation:
I didn’t have a glucose meter with me, so I can’t tell you what my ‘real’ blood sugar was, but it wasn’t this low. Very different pattern!
As long as we’re comparing, check this hot mess out. No trouble at all on insertion, but these 24-hour readings… 
I can assure you I was never anywhere near the 50s–this is off by 40 points when I’m low–but it took a night of waking up to do fingersticks to confirm that. I ordered a replacement, obviously.
I have stopped inserting the G6 in the evening because of this problem. It sucks to get an alarm at 3.00 in the morning only to find out that it was the sensor behaving erratically. So I always insert my sensor in the AM - then it can go wonky in the afternoon.
@CarlosLuis I had a similar occurrence to yours with a G6 several months back, it was the last period for the transmitter so I don’t know if the cause was the transmitter or sensor. My wife was in the room when put the sensor on and she noted she’d never seen me jump like that, let alone the expletive I uttered. It subsided after a few seconds, but my arm still ached. Like you, I chalked it up to nicking/hitting a nerve and hope it remains a “few and far between” phenomena. The first day “jumpiness” was terrible with intermittent jumps of 20-30 pts. It seemed to settle down for the next 7 days, but would experience the same jumpiness for short periods, then settle down. I removed it day 7 or 8 because the jumpiness became more routine and I just didn’t want to deal with it anymore.
This happens to me when I’m sleeping and roll over and stay in that position so there’s pressure on the G6. Blood sugar drops super low when it’s actually much higher.
That surprised me when it happened so now I sleep only on my back. Doesn’t sound like you have the same problem but just wanted to explain circumstance when I went through the same thing, 
Thanks @Shecamp. I have heard about this effect. But I sleep mostly on my back so it doesn’t explain my particular wierdnesses.
