There is a small window of opportunity above your triceps and below your shoulder that your Dexcom sensor can appropriately reside. If you aim too low, your arm will let you know with a constant “pinch” whenever you move your arm in any direction. It’s not comfortable. You’ll also know that you missed the mark because your receiver will display one of the following graphs over a 12-hour period:

• Nothing
• Radical shifts in readings – such as 80 mg/dL to 300 mg/dL in 30 minutes
• Nothing
• or Nothing

I had one of these bouts on Wednesday and as a result, had to remove a fresh sensor from my right arm. I discovered that this sensor caused a fair amount of bleeding at the insertion site, which justified the lack of data. I suppose a sensor lasting 33 days balances out a sensor barely lasting two hours, but it’s still a bummer to have to toss a sensor out after such a short time period.

Of course the biggest bummer is that can’t call Dexcom and complain with a clean conscience – having put this sensor on a non-FDA approved location – but again, 33 days. Let’s focus on the good.

I inserted a new sensor Wednesday evening, without any abnormal pain, and am happily back on the data-overload express.

If there is a lesson to be learned, it’s something along the lines of: be careful when inserting a Dexcom sensor in your arm and make sure you know where your triceps end and your shoulder begins. Anatomy, folks.

Learn it. Love it. Live it.