Small drop of blood - high reading

I can’t easily describe this one to search,but here goes…

If I have trouble getting enough blood to test, and I have to reprick my finger to complete the sample, I get a high BG. If I immediately run another test (this time with enough blood), I get a “normal” reading.

Meter is an Accu-Chek Compact Plus. The support people at Accu-Chek are trying to tell me that it wouldn’t happen. I’ve had this happen enough times to guarantee that I will easily be 30 points lower on the second test less than a minute later.

Anyone else had this happen? Any idea why?


I have experienced this also but not sure why that is. Mine is a One-Toiuch Ultra.

Wash your hands before testing. ANYTHING on your hands can affect the reading; even an unnoticeable amount of dirt. Trust me on this one. If you cant wash, use an alcohol swab to clean your finger.


i have had this happen as well- last night i was super high… meter said 487. i did a second check just to make sure- before i gave myself enough insulin to kill a small pony… 533. just washed hands. different fingers. it happens enough that i’m not surprised when it does. it makes me wonder just how often it really happens because i usually don’t question the results of my first test.

Hi Wynot,
This happened to me just last night. I had been putting away some groceries and thought i had better check my BG before starting to make my dinner. I got a reading of 554 and nearly fainted. I actually paniced for a minute and wondered if I hadn’t better call someone right away. After a couple of deep breaths I reminded myself to take stock of what was going on. I felt fine. I didn’t feel like I was in trouble. I remembered to go over and wash my hands and just recheck. Sure enough I was at 161. That isn’t a number i am comfortable with and started to recheck again but then remembered the more I check it the more it will change. So i shot for what i thought it was and knew i would check again after awhile and would also prepare for a low if one was coming. I think that if our meter messes up we should check when we put in a new battery or remind ourselves to wash hands. and not panic like I did. I felt kind of silly for getting scared right away but sometimes the meters mess up too. If it happens too often you might want to do something about your meter.

You should definitely wash your hands before testing (to be honest, I sometimes forget) because dirt etc. on your hands can influence your readings. And the smaller the blood drop the more noticeable the effect will be, because the dirt gets ‘diluted’ in a bigger drop and is more ‘concentrated’ in a smaller drop.


Yeah I’ve had that happen.I agree with Kat that you should probably wash your hands first.It gets the blood circulating,especially if your hands are cold.I also file my skin on my finger tips because they become calloussed.I have had readings five points higher than the last.When it gives me a reading that doesn’t really sound right I redo it.What I mean is knowing what I ate, how much and by how I feel.

I’ve noticed the same thing with the Freestyle Lite - with washed hands, etc. Sometimes they can be finickly little buggers, those glucometers. I remember (about a week after diagnosis) getting a 495, with the follow-up being at least 300 points lower. The tech isn’t perfect, but it’s better than dip sticks.

I keep little alcohol pads in my meter case. Clean hands do make a difference. I also have 3 meters, so I can check to see if it’s a “hardware” problem.

Of course, if all the alcohol isn’t off, you’ll have an artificially low reading . . . damned if you do, damned if you don’t.

For this reason, Kristin (one of our admins here) says she always uses a second drop of blood from the same finger prick. Usually it is a case of residue on your hands. I agree with the “wash first” crowd, though I’m bad about doing that.

As I’ve looked through the replies, I think I may have mislead the issue a little bit. My question is more about why having to get additional blood to complete the sample is causing a seemingly high reading. Maybe an example would help. I think I have enough of a blood drop for a sample, turn the meter on, it beeps, I apply the drop to the strip, it sucks up the blood and then nothing. It doesn’t have enough blood for the sample, and the meter sits there waiting… I quick either see if I can get any more blood out of the original prick, or just reprick another site, to get enough blood for the sample to complete. Finally, it beeps that it got enough blood. Guarantee that I will have a high BG reading. When I get the high (out of norm) reading, I immediately do another test, this time getting enough blood, and a normal reading. That’s the question. Hope that helps…Thanks.

Hi, we were told to always use the second drop of blood, and we do. When we see a needle like drop of blood, we wipe it off with a tissue and take the second one.

We tried taking the first one and tested the difference between the first and the second one and it makes a big difference in the reading (the first one is higher than the second one).

So, I guess if you add blood to a half filled strip, than it’s normal to have a very high reading.

Hi Gina,

I keep seeing this reference to the 2d drop of blood, what does that mean? If referring to the same test site, I’ll probably be clotted before I could possibly get a second drop out of it. And like most people, I ain’t thrilled about pricking more than I have to…

I will say that I almost will always get a lower reading on any second immediate test, but always put it down to meter variance.


Squeezing your finger to help the blood get out can get some of the intracellular fluid (not the same as blood) out of your finger, although this usually influences the reading in the opposite direction.

Having anything containing sugar on your finger can raise your readings; a good reason for washing first.

Some people over on the diabetic newsgroups have found that they can do some of the pricks on the sides of their fingers, and therefore avoid pricking their fingertips too often.

I have the same issue with multiple glucometers. I believe the issue is that the blood is more concentrated when you need to add that second drop, causing the meter to think there is more glucose in the test volume. On the other hand, when I have trouble drawing blood because my hands are cold, a large enough drop to get a reading will usually read about 20 points low. As a result, during the winter months, I tend to rely more on forearm testing than fingertip testing.