Got diabetes questions? You came to the right place! Ask D'Mine is our weekly advice column, hosted by veteran type 1, diabetes author and educator Wil Dubois.

This week, Wil tackles a pair of questions about blood -- when there's too little or too much for your D-testing needs. Read on...

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Debbie, type 3 from New Jersey, writes: I sometimes make the mistake of not putting enough blood on the test strip when I help my T1 boyfriend check for his level. I don't really make this mistake ALL the time, it's just that on the rare occasions that I do, it always upsets him. I think he feels that it's a waste of good test strips and he doesn't even trust the reading anymore. He already sees it as inaccurate. Thing is, we never recheck after that, so we don't really know if the meter comes up with the same level, if it was half-full, two-thirds full or even full. So I just wanted your input on that... Does quantity of blood on test strips affect the accuracy of the reading? Is there a minimum? Any experiences?

Wil@Ask D'Mine answers: Tell your boyfriend that I said he's being a butt-head. He should be damn grateful to have an engaged type 3 like you who wants to help out! You are a rare and wonderful find, and he owes you flowers big time.

But that aside for the moment, your question is a really good one. And there's no universal answer, because different types of strips vary quite a lot when it comes to how much blood they need in the first place, and how they cope with a shortage of blood in the second place.

Just to put it all in perspective, Abbott's FreeStyle strips boast the smallest sample size requirement at 0.3 microliters, while something like the not-so-prestigious Nipro BloodSugarCheckPrestige meter takes a full 4 microliters. That's like quite a difference (1,233% percent) but we're splitting hairs here. Well, splitting a blood drop that's one-millionth of a liter. To be honest, I don't even have a good way to show you how big a microliter blood drop is. I was going to tell you it's the size of the "o" in the word "drop," but even that's no help as it depends what font you are looking at, and how you've got the magnification of your computer screen set. The bottom line is that all modern blood glucose meters test using drops of blood the size of the head of a pin — it's just that some require larger pins than others.

In theory, if you grab the wrong pinhead for your strip, and you short-change the meter, most meters will give you an error message to which the proper response should be a long string of expletives followed by a re-test. Additionally, many meters have a "preview" window on the strip that should turn fully red when the strip has had its fill. But despite both of these precautions, meters can and will give false results when under-fed. Generally, but not always, they err on the high side, giving you a reading that's anywhere between a little higher than you actually are, to waaaaaaaaaaaay higher than you actually are.

But what's the point of no return? Would 10% short be OK, but 20% give you a "bad" reading? Is it linear? I have no idea, but I have a rule of thumb — well, more a rule of finger: Be suspicious if the strip sucks your finger dry. So long as there's a bit of blood left on your finger when you test, the meter got enough.

In other words, always over-lance. If you have a meter that requires 0.3 microliters, lance for 0.4. If you meter requires a full four microliters lance for five. Just get a little more blood than you need and you'll be fine. Then you won't need to shake and squeeze the finger in an effort to "pump" more out.

And what about the extra blood? Well, as it just so happens, I got a question about that, too:


Jessica, type 2, from Nebraska asks: What do you do with the left over blood on your finger after testing?

Wil@Ask D'Mine answers: There are two camps: Lickers and Dabbers. Both are kinda gross in their own way, and members of each camp are totally grossed out by members of the other.

Lickers just lick their fingers off after testing and get on with life. There's no biohazard as it's their own blood, and as everyone washes their hands before testing, there's nothing nasty from the environment that's going to get into their mouths. You do always wash your hands before testing, right? But while you dabbers are cringing, consider how many times you've seen non-D-folks lick the blood off of small injuries.

Dabbers, on the Heart Dabsother hand, clean off their fingers on something after testing. Often it's a folded napkin or Kleenex carried in the meter case. Other times it's a dark piece of clothing, such as a sock or pants cuff. Interestingly, there's actually now a product for dabbers called Diabetic Dabs that was developed by frustrated T1D mom Liz Sacco, who was driven to distraction by her 9-year-old son's habit of wiping his finger randomly on his clothes. Sacco estimated that over a two-year period, with her son testing six times a day, she was responsible for cleaning up 4,000 pieces of stained clothing. Sacco's Dabs are small adhesive-backed pads of 50 absorbent sheets that can be attached to the inside of the meter case for a tear-and-go solution at each test. She makes them in both squares and in heart-shapes. Gotta love that.

I (heart) testing?  Hee hee...


Sorry. Let me drink some more coffee and sober up. In general, what I see in the field is that type 1s are more likely to lick it, and type 2s are more likely to dab it. That said, I do know a couple of squeamish T1s and some more laid-back T2s. Among the type 2s, the higher their testing volume, the more likely it is that they'll lick.

Me? I started out my diabetes career as a dabber, but I was kinda grossed out by having a tissue covered with dry crusty biohazard-looking stains in my meter bag. Then the TV show dLife launched, and I saw co-host Jim Turner lick his finger off.

You can do that? On Network TV?!

I converted on the spot. And no, Dabbers, no matter how high my blood sugar is, it's never tasted sweet to me. If it did, we'd all test more often just for the flavor high.

Personally, I find it fast, easy, and clean to lick and run. Plus, it's also fun that every time I do it at work my otherwise hardened-to-everything nurses nearly faint.

That's because they've been trained to be dabbers.



This is not a medical advice column. We are PWDs freely and openly sharing the wisdom of our collected experiences — our been-there-done-that knowledge from the trenches. But we are not MDs, RNs, NPs, PAs, CDEs, or partridges in pear trees. Bottom line: we are only a small part of your total prescription. You still need the professional advice, treatment, and care of a licensed medical professional.


Disclaimer: Content created by the Diabetes Mine team. For more details click here.


This content is created for Diabetes Mine, a consumer health blog focused on the diabetes community. The content is not medically reviewed and doesn't adhere to Healthline's editorial guidelines. For more information about Healthline's partnership with Diabetes Mine, please click here.