Dexcom Sensor bleeding - not much but is it normal?

So, I got my Dexcom this afternoon, applied it and it did bleed a bit under the needle point under the sensor. It just completed the two hour warmup and it’s functioning properly. I also calibrated it and it was only 2 points off what my blood glucose meter showed, so all is well there. My question is, is the bleeding normal? I put it on my stomach to the left of my belly button by 2.5-3 inches. I did pinch the skin up when I clicked the button because I didn’t want it to hurt and I had never used one, so wasn’t sure what I was up against. I’m wondering if thats why it bled? But there is no pain, was no pain, so next time I won’t do that. The bleeding the last I saw was about the size of a kernel of corn in bleeding (weird visual but its the best I can think). Normal? Not? I called Dexcom and the first guy I talked to said no its not normal; they passed me to tech support and that lady said it happens sometimes; my son who is also type 1 said it happens to him sometimes too. There is no bleeding or blood in the white cloth part surrounding the actual sensor piece so am I good? Called my doctors office, waiting on an after hours call from the doctor on call. Curious what your experiences have been. Can I take the gray piece out to look at the blood underneath or will that mess everything up? Thanks for the help!

UPDATE: Talked to an on call doctor at my endo’s office and she said as long as it’s not seeping into the white part of the dexcom adhesive and it’s not painful I should be fine. She said it’s a very shallow needle so it shouldn’t have come close to any major veins or anything. So, I’m probably gonna leave it where it is and let it be.

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It’s been a long time since I’ve had bleeding with my sensor but it has happened. I’ve gotten a little bit similar to what your described but it stopped and didn’t affect my readings. I think once or twice I’ve had one soak through the tape. Again that was a long time ago - I don’t think I even waited for the warmup to finish before I called Dexcom and requested a replacement, as I was not comfortable leaving it in. I’ve been using a CGM for over 20 years and that is exceedingly rare.

@HisWifeTheirMama Oh I’ve shot sensors (annd pulled out infusion sets) and my kitchen looked like a murder scene in the past. My experience is “bleeders are readers”. Consider it good luck! :shamrock: if the sensor fails or falls off before 10 days you get a new one from dexcom.

Sarah @HisWifeTheirMama, bleeders like what you experienced are not unusual and also not normal. Yet, what you describe the little bit of blood does not affect the sensor accuracy, lifespan or usefulness. Similar to your son, I have a few bleeds like you experienced per year.

You can not see the sensor until you remove it from your body. The sensor is a very fine platinum wire that is now imbedded in your body; it attaches to the plastic shoe, held firmly in place by the “tape” and holds the mini computer that interprets glucose below the surface of your body and used the included BLE transmitter to send values to your Receiver.

I am hesitant to try any calibration during the first half-day of sensor readings; doing a calibration can cause the sensor to, in effect, begin a new warmup to learn your body. Also, never calibrate with a finger stick BG Meter if readings between the two devices is within 20%/20 mg/dl; there is a calibration table for your use in the Q&A section of Dexcom website.

BGM and CGM reading values can be significantly different and mean exactly the same thing; they measure different substances and provide different information. A BGM uses surface capillary blood and gives a present-time value of fre-flowing glucose that hasn’t been observed into the body. A CGM obtains its reading from interstitial fluid that surrounds body cells - the glucose that the body has absorbed and put to work within you - excessive amounts maybe causing harm and, just-right amounts helping you to move around and to think. Keep in mind too, that your Dexcom G6 is predictive, the digital value may at times be indicating where you may be in 15 - 30 minutes. Before using your G6 for insulin dosing, always look at at least 4 consecutive sensor dots and use best judgement for an insulin injection.


Here’s a screenshot of the Dexcom calibration table @Dennis referred to:

I’m going to be an echo chamber and affirm that yes my dex bleeds sometimes after I insert it. Sometimes a lot, sometimes a little. It doesn’t usually have an impact on my BG readings. Sometimes it’ll soak through the sticker. If you don’t like how that looks I’ve found that a hot shower usually helps to remove the blood stain from the sticker.

Like @wadawabbit said, if your dexcom falls off or starts to peel or is super inaccurate, fill out the form in your dexcom app or call them to get a free sensor replacement. I do this when I have issues and usually end up with an extra month’s supply of sensors which has been really helpful in the past when I go on vacation or if prescription renewal is delayed.

I usually have a 1 in 5ish chance of bleeding when I put on my Dexcom or Omnipod. I’ve only had trouble with one Dexcom, and I’m not entirely sure if the bleeding and connection issues were related. Bleeding is 100% fine and it happens; I mean, there’s a needle piercing your skin. Sometimes there’s just going to be blood, and that’s okay.

@HisWifeTheirMama My thought is that there are those that have and those that will experience a Dexcom “bleeder”. I and many others have experienced the surprise “leaker” and even a “pumper”. They aren’t what I’d call “common”, but they aren’t unheard of either. They usually stop relatively quickly, though the rare ones will seep for several minutes. Most will use a tissue to “wick” the blood away until it stops, but if it seeps for a longer period it can affect the adhesive and some replace them and report to Dexcom as failed (they usually replace them). There’s been discussion on the effect of bleeders on accuracy/performance, some feel there is, some say no; I’m in the camp of try a couple of finger sticks, calibrate if necessary, and if it’s too far off or not reliable, then take it off (replace), report to Dexcom, and ask Dexcom to replace it. I recommend using the form they have on line vs calling in; seems quicker and most of the tech support folks I’ve spoken with seem to try to talk you out of or deny replacements (like they get paid more the less replacements they make…my opinion, not known fact).

There’s been a lot of discussion about placement. Dexcom has endorsed certain placements (see their website) for their different products. I personally think it’s more “we tested these locations and that’s what we asked FDA to approve”. I and others have tried thighs (inner/outer), stomach (avoiding the immediate area around the navel), arms (bicep/tricep, inner/outer/back). I know some have tried ankles, backs, necks (ouch!), butts, etc. Some work for certain people, some don’t; placement is very individualized. I tend to use the outside of my left arm, it works for me and avoids compression lows (sleeping on the sensor sometimes makes it not work, hence alarms). My recommendation is start with the Dexcom advertised locations, get a feel :laughing: for the device, then branch out and see what works best for you/yours; you may need the space for a pump, injections, medical tests/treatment, surgery, or what have you. If one fails and you call in to Dexcom, don’t be dishonest or lie, but don’t offer info they don’t ask you for or are entitle to either, some of their “customer service” folks will refuse replacement of a device not strictly following Dexcom’s guidance; tough I haven’t had one ask me, “How far from your navel was the device?”…not yet anyway!

BTW, I haven’t checked personally, but I’ve been told by a Dexcom rep the G6 needle inserts the wire 6mm and the G7 only 4mm. It may make a difference whether you stick to “fatty tissue” or try “leaner” areas.

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@Tlholz G7 is 90 degrees and 4mm platinum wire sensor length. G6 is longer because it is an angle insert. G7 is also thinner wire (0.008 inches).

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The first site I put in after training with the G6 bled a little which alarmed me enough to call the trainer because my Guardian Sensors rarely bled for whatever reason. My trainer said what joe said above: 'bleeders are readers so I don’t worry about it unless it bleeds a lot. The one time it did that, I took it out and requested for a new one. But once in two years isn’t much IMO.

As for calibration, I probably only have to calibrate once in every three or four new insertions. I mainly do this when it says I am low and I don’t feel low, or (much less often) when it says I am high and I don’t feel that way.

Don’t need to pinch before attaching sensor. Bleeding is ok, but I do calibrate and check it specifically if blood sugar level is too high or too low, it may be incorrect. I have had sensors and Omnipod that bleed and still work!

Hi Everybody,
For all the Dexcom G7 users- Dexcom recommends NOT calibrating during the first 12 hours, at least that’s what their representative told me last time I called complaining of inaccurate readings. He said it’s warming up during that time and to rely on fingerpricks if the sensor readings don’t match how you feel. Same with the Libre 3 (where calibrating isn’t possible & the same 12 hour warm up time exists).
Lots of people seems to have fairly accurate readings earlier than the 12th hour, but I generally don’t. So I overlap= apply a new sensor at least 12 hours before the older one expires.

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One more reason to keep the 6 for me. I have no idea how to overlap the new one without stopping the first. Frankly, I tried with the 6 and of course it started counting once I stopped old sensor and started new one.

Edith, take courage, the G7 really is very easy to use - may be easier than the G6.
May I suggest that you try to ignore postings on here with tricks suggesting that ‘You “work” the system’ that ain’t broken. If you just follow the Dexcom printed material packaged with each G7 I think you will be happy - here is the official method: G7-Start-Here-Guide.pdf (

I’m new to the G7 so I’m not offering any tricks, but I’m liking what I see. The G7 began giving me readings 28 minutes after I pushed the start button and during the first couple of hours I received what appeared to be odd readings - most of the “weird” appeared during what was the 2-hour warm-up of the G6 when I didn’t get any readings at all. YES, I started a new G6 within one minute of beginning the G7 and I’m two series of readings on the same graph - I’ll report later on my findings. So far, my observations indicate that the G7 may be better for me. Each sensor is in the Dexcom preferred location: G6 abdomen [on my left side] and G7 triceps [my right]; I tend to roll in my sleep from one side to the other and, so far, I haven’t had “compression low” in either.

Best wishes!!!

Edith, Here’s a string discussing how to overlap the G7, it’s easy. If you have any questions related to doing this, please circle back.
G7 startup overlap? - T1D Tech & Daily Management Support - JDRF TypeOneNation Community Forum