Dang…hit a blood vessel with the new sensor

I just inserted a new sensor for the Dexcom, and hit a blood vessel. After waiting a few minutes, I went ahead and put the transmitter in, and will wait a few hours to see if it still works.

My last sensor was perfect and I gave a little bow to it several times a day. : - )

Anybody else have experience with the blood vessel thing? Should I just assume the sensor needs replacing?

Hi Sarah,

I had this same problem not too long ago. Here is the thread:


Basically, my sensor worked perfectly fine after inserting! I can understand wanting to change it because of the blood, but I think unless the sensor is reading wacky numbers for a whole day or two, you’re okay.

I've had this happen twice. Once the sensor never reported valid numbers and I replaced it after a day or so. The second time it was fine. So ... your mileage may vary. Best luck!

Did this once and it was still accurate. You will just have to give it a chance.


Thanks for sending the thread….where is the "search" function on the discussion page? I tried to see if it had been discussed before and nothing came up. Am I missing something obvious?

In any case, it's great to have other people chime in with their experiences.
The sensor is still in, it's been 4 hours and readings seem accurate; however, it hurts a bit which is unusual for me, so I may just pull it and find another spot.

To be honest, I have no idea how to search. Haha the only search function I can find did not pull up my thread when I typed in "blood," so that one doesn't seem too useful. I know that improving search is currently being discussed as one thing that could be improved upon in TuDiabetes.

If it hurts, that would be another thing to make me want to pull it. I usually wait a few hours more to see if the pain subsides, because often it does, but it's too uncomfortable and worrisome to leave a painful sensor in.

When that happened to me, I tried calling Dexcom to see what I should do about it, but the line was busy for hours and hours, so I pulled it and put in a new one. Later, when I finally got through, they told me it should be OK, even if there is a relative lot of blood, but since I had already pulled it out, they sent me a new one.

That happened to me today.I bled under the sensor but numbers seemed to be okay.I sometimes have my sensor to be off about 1.7mmol,but I know there is a lag and it takes about 15 in to catch up to the blood.I have only been using the cgm for 1 week.I am starting to learn how it responds.

This happens to all of us at one time or another! I dislodged the sensor trying to dab up the blood–Dexcom replaced the sensor without a problem (except for a bit of telephone tag). I now look really carefully for a blood vessels under bright light begore selecting an insertion site. So far, so good!