12 Common Mistakes When Testing Blood Sugar with a Glucose Meter and Test Strips

For anyone living with diabetes, the key to avoiding diabetes-related complications such as heart disease, nerve damage, eye problems, kidney disease, and the dangerous onset of hypoglycemia, is to proactively manage blood sugar levels.

The only way to control your blood sugar is to test it regularly, and to do this most people with diabetes rely on a glucose meter and test strips. The good news is this is an extremely easy and accurate way of measuring blood glucose levels. Still, there are some common mistakes made when testing that can lead to inaccurate measurements, as well as patient confusion and discomfort. The last thing you want to do is compromise your diabetes treatment plan by compromising the reliability of your blood sugar test results. Fortunately, blood sugar testing mistakes are pretty easy to eliminate from your diabetes testing routine, and, as with most aspects of living with diabetes, when it comes to testing blood sugar, the more you do it, the better you get at doing it correctly.

What follows are our Top 12 mistakes to watch out for when testing your blood sugar. Avoid these mistakes and you’re sure to improve your blood sugar testing accuracy and become a lot more confident each time you prick that finger.

  1. Choosing the wrong glucose meter

Most of the glucose meters you’ll find on the market today from leading manufacturers, such as OneTouch, FreeStyle and Accu-Chek are all very accurate ways of testing blood sugar. However, they’re not all the same. Some are able to transfer data to your smartphone. Some can store 500 test results; some can store 1000. Some have oversized, easy-to-read digital displays and some glucose meters are small enough to fit easily in your pocket. Convenience is a big part of developing a regular testing routine and that means choosing a glucose meter that fits your needs and lifestyle. Which one is right for you? That depends on age, vision, mobility, testing frequency and more. Rest assured; your diabetes physician will be happy to make some good recommendations to help you choose a glucose meter that works for you. 

  1. Not setting up your meter correctly

With today’s advanced technology, there’s really not much to setting up a glucose meter. That being said, one of the most important aspects of reliable testing is setting the time and day correctly on your meter. After all, you and your diabetes physician want to know your blood sugar levels at very specific times. If the date and time on your meter are not accurate, your test record will be very difficult to follow, and, therefore, it will be much harder to make confident adjustments to your diabetes treatment plan.

  1. Not washing your hands correctly prior to every blood sugar test

It doesn’t matter if your hands don’t look dirty. It doesn’t matter if you washed them earlier in the day. Any residual sugars from foods you might have eaten since washing your hands last, or any elements you might have picked up that might contaminate your test results, must be removed. To ensure the accuracy of every blood sugar test, wash your hands thoroughly with soap and warm water, and dry them thoroughly afterward. Avoid using alcohol swabs or antibacterial hand sanitizer as prolonged use can cause drying and discomfort. Additionally, many experts believe washing with alcohol can lead to a lower blood sugar reading than is actually the case. While this may be debatable, you won’t ever go wrong washing with soap and warm water.

  1. Not getting enough blood on the test strip

You only need a small drop of blood to get an accurate blood sugar measurement from today’s glucose test strips. However, you do need a solid drop of blood. If you don’t get one, it can lead to inaccurate blood sugar readings. To make matters worse, not being able to get a good drop of blood often leads people with diabetes straight to our next blood sugar testing mistake.

  1. Squeezing your fingertip to force more blood out

Even if your finger prick isn’t emitting an adequate blood droplet, you never want to squeeze your fingertip in order to force more blood out. Along with  blood, you’ll end up bringing forth some interstitial fluid, which can compromise your test results and lead to unreliable blood sugar readings. Here’s a tip to avoiding this problem, which is often cause by a lack of circulation or cold hands. Try warming your hands ahead of time by rubbing them together or even running them under warm water for an extra minute or two after washing. 

  1. Pricking the same finger every day

This is somewhat of an indirect accuracy issue, but it can be a big one. Pricking the same finger for repeated blood sugar testing can eventually become rather painful. We all know, when things get uncomfortable, they become a whole lot easier to forget about or avoid altogether. So, switch up those fingers. Testing accuracy is not compromised in any way by using multiple fingers to test your blood sugar. We recommend switching up your testing finger at least every day, if not for every test. It really depends on how often your doctor recommends testing and what works best for your diabetic treatment program. One good habit is to follow a regular pattern or sequence for testing each day or week. For example, Monday it’s the first finger on the right hand. Tuesday, it’s the first finger on the left hand, etc. This gives each site adequate time to recover.

  1. Pricking the pad of your finger

The pad of your finger is loaded with nerve endings, and repeated pricking can lead to discomfort. Besides, the pad of your finger gets a lot more use than you might think - typing, playing musical instruments, pushing buttons - all put pressure on your finger pad, which, if irritated, can compound the discomfort. Instead, test using the side of the fingertip. It doesn’t matter which finger or which side as long as there is adequate blood flow.

  1. Using expired or incompatible test strips

Expired test strips can’t be counted on to deliver reliable readings and should never be used when testing blood sugar. Always use fresh test strips that you’ve opened for the first time at the moment of testing. Diabetic test strips tend to have a long shelf life and all packages should be labeled with clear expiration dates, making this an easy problem to avoid. Additionally, it’s important to use test strips and lancets that are compatible with your glucose meter. This will ensure you draw the right amount of blood and test with a manufacturer-approved strip for maximum accuracy.

  1. Reusing lancets

This is an absolute no-go for anyone with diabetes. For starters, lancets dull rapidly because they are not made for multiple uses, which can lead to considerable discomfort at the prick site. Beyond more pain, a dull lancet can result in an insufficient or contaminated blood draw causing an inaccurate blood sugar reading. Additionally, reusing lancets greatly increases the risk of infection. In the end, it’s just not worth saving a few bucks. The general rule is this - one lancet, one test. After each prick, discard the used lancet in accordance with proper diabetes waste disposal guidelines.

  1. Testing postprandial blood sugar incorrectly

Postprandial blood glucose testing is designed to measure blood sugar levels two hours after eating. It seems logical that you’d take this test two hours after completing a meal. However, it’s best to begin the two-hour countdown at the beginning of the meal rather than once you’ve finished eating. Avoid this simple mistake and you’ll see more accurate blood sugar readings.

  1. Testing your blood glucose level too randomly

The whole point of measuring your blood sugar is to see what impacts your blood glucose levels. Your diabetic physician will provide you with a clear testing schedule, which will likely include testing blood sugar before and after meals, before and after physical activity, right before bedtime and any other time your doctor deems important. Stick to the schedule, unless, of course, you feel any telltale symptoms of low or high blood sugar, in which case you should test yourself immediately.

  1. Not tracking blood sugar test results accurately

Taking accurate blood sugar readings is important. Keeping track of those accurate blood sugar readings is equally crucial to managing your diabetes. Your physician and care team will surely provide some good assistance - including recommending the right glucose meter to test and log your measurements. Unless you carefully track your blood sugar ups and downs, it’s impossible to pinpoint the influences that lead to blood glucose fluctuations. In other words, tracking your blood glucose levels is how your doctor knows whether or not adjustments are needed in your diabetes treatment plan, be it lifestyle changes or medication changes. The bottom line is this: if you don’t properly track your test results, you’re essentially flying blind and that’s not a good way to control your blood sugar or manage your diabetes.

We hope you found this post helpful. Should you have any questions about blood sugar testing, the best source for information and answers is always your diabetes physician and care team.

At Diabetic Warehouse, we do our best to keep you updated and informed on what’s happening in diabetes care and treatment. We’re also committed to saving you up to 65% on a complete online selection of diabetic supplies, including glucose meters, test strips and lancets, insulin syringes, pen needles, continuous glucose monitoring (CGM) systems, and om, Easy Comfort, True Metrix and others. See reviews from our satisfied customers and explore our great selection of products at Diabetic Warehouse. We provide free delivery with every order to your home or office.


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1 THOUGHTS ON “12 Common Blood Glucose Testing Mistakes”

by douglas

I am fairly new to testing but I wanted to know if it is possible to get 3 different glucose readings from the glucose meter? My meter is brand new from my local pharmacy. What is the best course of action? Should I buy a new blood glucose meter? If so, which meter is the most accurate? Thanks.