How Do You Know If Your Glucose Meter is Accurate?

A blood glucose meter, also known as a Glucose monitor or a glucometer, is essential equipment in managing your diabetes. The device can tell you what your blood sugar is at the moment. Earlier, people check their blood glucose level using a urine strip which only exhibits results when your glucose levels are high enough to spill over into your urine. So, they were not considered as much adequate. 

As compared to the urine strip, the glucose meter is considered more reliable. When you put your blood on a ribbon, the glucose in that sample reacts with the chemicals in the strip setting up a small electric current, which the glucose meter reads. The more glucose that is in the model, the higher will be the current and the reading. 

A glucose meter will help you know your current blood sugar level to have information about your food choices and how much you should eat, your exercise level, and if you take insulin, then when should be your next dose. 

Besides that, reading can give you and your doctor an overview of how your body responds to a particular food, exercise, or a specific medicine. Regular glucose monitoring can help you stay fit and healthy for the long run. 

How to Check the Accuracy of the Blood Glucose Meter?

However, people using a glucose meter to keep an eye on their blood sugar level often think how accurate is the glucose meter? The answer to this question is the accuracy of blood glucose is usually determined in two ways-

  • Lab test performed by a professional healthcare provider
  • Personal blood glucose meter

How Are These Tests Different?

The personal glucose meter computes the blood glucose using a sample from your fingertip and then analyses the whole blood (including red blood cells and all).

On the other hand, in a lab test performed by a professional, the sample is taken from a vein from your arm and treated to remove blood cells so that only the plasma is tested.

Which Is More Accurate?

Compared to both, the lab tests usually determine a higher level of accuracy than a personal blood glucose meter. However, even these machines can have a slight chance of error. Blood glucose meter tests are also not the same, but they are designed to provide accurate readings for daily treatment decisions. 

But certain factors can cause the two readings to vary slightly, but usually, a result from a meter that’s within 15-20 percent of your lab reading is determined accurately. So, if your lab results say that your blood glucose is 100 mg/dl, then your meter might report your result as 85 mg/dl or 115 mg/dl and still be considered accurate. 

Factors That Can Affect Glucose Meter Accuracy:

Mentioned below are few factors that affect the accuracy of glucose meter-

  • Test strips

When you use test strips, the glucose in your blood combines with enzymes on the strip. This releases electrons, developing an electrical current. The device then converts that into a concentration of glucose to provide you a reading. And because the process is complicated, your test strips can be very sensitive to variables. Inaccurate results can come from test strips if-

  1. If the test strip is damaged or expired
  2. If the strip is affected by heat or moisture
  3. If the ribbon does not have enough blood applied
  4. If the test strip is not designed for your meter
  5. If the test strip has contaminants on the sample area
  • Environmental factors

The grouping of your test strip, along with your blood flow and composition, can be affected by the outdoor environmental conditions. A component in the test strip chemistry called an enzyme can be sensitive to temperature and humidity conditions. Temperature and humidity can cause enzyme activity to decrease and affect the accuracy of results.

Moreover, your body also reacts differently at different temperatures. High temperature can make it easier for you to become dehydrated and raise your glucose levels, while the low temperature can affect circulation and lower blood flow to testing sites.

  • Substances on your skin

Any substance you touch on your skin can result in your blood sample and on your test strip. Since many meters use a micro-sized blood sample, just touching something that contains sugar and not washing your hands can affect your readings. If you currently washed your hands, but they are not completely dry, the water left on your fingers can dilute the sample.

  • Amount of blood in your test strip

It might be possible that too much blood or insufficient blood in the test strip sample area can also lead to an inaccurate result. 

  • Meter variances

The measurement process, enzymes, and algorithms in every meter on the market are different. Each brand’s manufacturing, calibration process, and chemistry is different. Even if you are using test strips of a similar brand, you can experience its variations in the morning and night readings. 


Managing diabetes or blood sugar levels can be challenging, but when you include it monitoring regularly, you can have a watch on your everyday glucose level. A glucose meter is a helpful device to monitor blood sugar levels. However, its accuracy can vary due to various reasons. However, the most important thing to keep in mind is to choose the best blood glucose meter.

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