Saying that operator error is the biggest problem that people who have diabetes have when we check our blood sugar sounds like blaming the victim. But I’m convinced that some mistakes we make when using our meters and test strips and lancets is the reason why testing so often gives us wacky blood sugar numbers.

People with diabetes know all about blaming the victim. For years I have argued against the common fallacy that diabetes is a lifestyle disease caused by our weight and sloth. In fact, most of us have diabetes in our genes, as the new science of genetic testing shows.

But sometimes -- and not always -- the victim herself or himself causes the error. That’s what is going on with some of the inaccurate readings that those of us who have diabetes often get from our blood glucose meters.

For more than 40 years, people who have diabetes have been lucky to be able to check their blood sugar levels at home and when travelling. We can do it whenever we need to do so. We don’t have to go to a doctor’s office or a hospital or a lab. Consequently, we forgot what a sophisticated testing device we have in our hands. Blood glucose meters are one of very few blood testing devices that the U.S. Food and Drug Administration lets untrained people use.

And we are for the most part completely untrained in how to use our meters. Is it then any wonder that we screw up the procedures once in a while?

Maybe the most common mistake we make is when we don’t get enough blood on the test strip. After using dozens of different blood glucose meters since a doctor told me almost 20 years ago that I have diabetes, I know from my own experience that when I don’t get quite enough blood on the test strip that the result the meter reports will be off. Usually, it will say that my level is much higher than when I test again right away with a full drop of blood.

Of course, the newer meters require much less blood than then did even just 20 years ago. Some meters can give us accurate results with a blood sample of just 0.3 microliters. That’s just a speck of blood, but when we use less than that speck, we still run into inaccurate test results.

We can run into problems even before we get enough blood to satisfy the bloodthirst of our particular meter. I can think of two such problems:

1. Have you ever lanced a finger that you didn’t wash just beforehand? If you happen to have some sugar on your finger, the meter could be reporting your dirty finger rather than your clean blood. Since starch turns to glucose in our bodies, I also wonder if having a little flour on our finger might work the same way.

2. Have you ever had to squeeze your finger a whole lot in order to get enough blood? If so, you might be getting interstitial fluid rather than blood. That might give an inaccurate reading. The way to prevent this is not only to wash your hands but to be sure to warm up our hands and the blood in them by using water that is about as hot as you can stand.