Earlier, diabetic people used to go for lab tests to measure their blood sugar level every time. But thanks to science and technology! Now, anyone can monitor their blood glucose level at home with the help of a device known as a Glucometer.
Both glucometer and lab tests are considered reliable and accurate. However, a glucometer is more convenient, which is why a diabetic person more prefers it.
Surprisingly, sometimes, many people face inaccuracy in glucometers. Some factors affect the accuracy of glucometer, such as the amount of blood, environmental factors, stress, etc.
In this article, we will discuss such factors in detail. So, let’s get started.
What Factors Can Affect Glucometer Accuracy?
Glucometers are small devices that measure your blood glucose level with the help of a finger-prick machine and a test strip.
If used correctly, glucometers give accurate readings; however, the following factors can affect the meter accuracy:
1. Test Strips
Test strips are one of the essential components of a glucometer. When you apply blood to the test strips, the glucose interacts with the enzymes on the strip, which creates an electrical current.
Then the meter converts it into a concentration of glucose that produces readings. Such a complicated process makes test strips very sensitive.
Test strips can cause inaccurate readings due to the following reasons:
- A damaged or expired test strip will not give you an accurate result.
- Any oily substance or dust on the sample area damages the strip.
- If your test strip is not made for your meter, then it shows inaccurate results.
Accuracy Tip:
- Always keep the test strips in their container
- Maintain the temperature that the manufacturer specifies
- Buy the test strips that are made for your glucometer
- Read the instructions carefully to avoid any testing errors
- Make sure that the test strips have not expired
2. Amount of Blood on the Test Strip
Your test strip requires some amount of blood to get accurate readings. If the blood on your test strip is more or less than needed, it will lead to inaccurate results on the glucometer.
Accuracy Tip:
- Read the required Blood Sample Size of your Test Strip
- Do not squeeze the blood drop directly around the lanced area.
3. Substances on your Skin
Latest glucometers use micro-sized blood samples to measure blood glucose levels. It means that anything on your skin, such as oil, moisturizer, lotions, and water, can affect the readings.
Anything you touch or put on your skin (mainly that contains sugar) can end up in your blood that changes the sugar level in your blood, leading to inaccurate results.
Accuracy Tip:
Wash your hands before finger-prick; not only wash but also dry your hands thoroughly with a towel before every test.
4. Extreme Temperatures
Enzymes in the test strips are very sensitive to humidity and extreme temperatures. They lower enzyme activity and affects the accuracy level.
Extreme temperatures can also affect your body. While high temperatures can increase your blood sugar level, low temperatures can lower blood flow.
If you test at high altitudes, it is also possible that the glucometer under or overestimates the blood glucose level.
Accuracy Tip:
- Make sure to keep the test strips at room temperature
- Avoid opening the container in case temperatures are extreme outside
- If you cannot feel your body due to high temperatures, wash your hands and keep them in warm water to improve the blood flow before doing the test.
5. Testing Site Location
Have you ever thought about why blood from a finger is taken to measure blood glucose level? Blood from other areas such as forearms, calf, and thighs show inaccurate readings due to physiological differences in the circulation of fresh blood in these areas.
After eating, exercising, or taking medicines, changes in your sugar level can easily get detected in your finger’s blood than in other body areas.
Accuracy Tip:
Always check the instructions given on the box of glucometer before using it.
6. Improper Coding
Some glucometers require coding; some do not. If you buy a glucometer with a coding system, you have entered the correct code printed on the test strip vial to calibrate it.
However, incorrect code leads to inaccuracy of readings.
Accuracy Tip:
- Make sure to enter the correct code and avoid even minor mistakes
- We suggest you buy glucometers available in the market that does not have a coding system
7. Monitor Problems
Problems in monitor such as a low battery or damaged battery can affect the accuracy of glucometers. Even a dirty monitor can affect the accuracy of readings.
Also, if the test strip is not appropriately inserted then also, it gives inaccurate results.
Accuracy Tip:
- Make sure that the monitor is charged and the battery is in good shape.
- Insert the test strip in the meter properly; therefore, reading the instructions is a must!
8. Meter Variances
Different brands and glucometer manufacturers have different calibration processes, enzymes, and algorithms that affect the readings.
So, if you measure your sugar level with different glucometers, then you will get different readings.
Accuracy Tip:
Measure your blood glucose level from one glucometer only. Do not change the brands frequently to get accuracy in readings.
The Bottom Line
International Organisation for Standardization (ISO) sets the accuracy standards of Glucometers. All glucometers available in the market have to meet these standards.
But all the above-given factors affect the accuracy of the glucometer and make them useless. So, it’s best to follow the accuracy tips while measuring the blood glucose level.

After completing this graduation in Electrical and Electronics Engineering from Manipal University in 2013, Ankit began rummaging the current Indian market of technology and science. At apolloedoc, Ankit’s job profile consists of cumulating, researching, testing, and verifying products related to tech.
He has a knack for details and catches even the tiniest advantages and flaws that can make or break the product. Since last year, he has been writing for apolloedoc and has been our knight in shining armour when reviewing home appliances.
Ankit’s favourite pastimes consist of jamming onto his guitar with a couple of friends and constantly updating and learning new things! He is also a big-time pet lover and has a cute little pug named Oreo back in Chandigarh. He has bagged many achievements in his college by participating in multiple extracurricular activities.
Writing is something that comes to Ankit naturally. He has his own blog where he posts about coding languages and even provides coaching to students from 12th grade to 2nd year of college. At apolloedoc, Ankit beautifully showcases his knack for the written word by lucidly explaining information in an unbiased way.