How to Accurately Measure Blood Sugar?

testing blood sugar

We go to our personal doctor for an annual preventive examination, do blood tests and among all the values ​​that we determine to be normal, stand out “Glucose – 6.89 mmol / L” with “Reference limits – 3.80 ÷ 6.10 mmol / L”.

At the moment we are thinking of the worst – diabetes.

This scenario is familiar to many people, but should we immediately think of the worst?


Let’s start with a few introductions.

What is blood sugar?

The term blood sugar refers to the content of glucose in the blood. Glucose is the main source of energy for tissues in the body and the most common indicator of the state of carbohydrate metabolism.

What is a reference value?

Depending on the analysis and the equipment it uses, each laboratory has values ​​that it considers “normal”. The value between the limits of these values ​​is called the reference. The most common reference values ​​are from 3.80 mmol / L to 6.10 mmol / L.

When is blood sugar measured?

The time intervals during which blood sugar is measured are three:

On an empty stomach – this interval indicates a period of at least 8 hours during which you have not consumed anything. Most often this is the period between dinner and breakfast.

Before a meal – this marks a period shorter than 8 hours. Most often, this is the time before one of the meals.

After meals – this is the period from 2 to 4 hours after eating foods containing carbohydrates. Depending on the number of carbohydrates, this period can be up to 8 hours.

What is needed to measure blood sugar?

Depending on the environment in which the measurement will be performed, the necessary tools also differ:

Laboratory testing – this method uses laboratory equipment, which can vary widely. For this reason, we will not consider this method.

At home – this measurement is associated with simple preparation and the availability of some consumables.

What is needed when measuring blood sugar at home?

For this purpose you will need:

  • Glucometer
  • Test strips
  • Lancing Device
  • Needle for the lancing device
  • Cotton
  • Ethyl/methyl alcohol 70 ° C

Preparation for the measurement

Preparation for measuring blood sugar is one of the stages in which most mistakes can be made. It involves selecting and cleaning the injection site.

Alternative Blood Sugar Testing Sites

Some modern glucometers are able to work with blood samples from alternative areas of the human body.

It is generally accepted that the blood sample needed to test the blood sugar with a glucometer should be taken from the ring finger of the left hand. The most famous reason for this is that this finger is used the least in everyday life.

Before taking a blood sample from an alternative place, make sure that your meter is able to analyze it, apart from your finger!

Cleaning the testing site

The puncture site should be thoroughly cleaned. 70 ° C ethyl/methyl alcohol and cotton are used for this purpose. It is important to clean the area with alcohol and dry it with another piece of cotton. Residual moisture can dilute the blood sample and adversely affect the result.

Cleaning can also be done by washing your hands with “soft”, not very aggressive soap, and then drying your hands with a dry and clean cloth.

A common mistake is a use of alcohol for direct consumption, as well as non-specialized wet wipes. These methods are not recommended because they contain sugar, glycerol, and other components that can affect the end result.

A light massage at the injection site will improve local blood circulation.


Once you have cleaned the puncture site, it is time for the actual measurement.

Remove one test strip, being careful not to touch it on the controls (usually the two ends of the strip).

Take the meter and place the tape in it at the place specified by the manufacturer.

Be careful, the direction of the test strip is important!

Use the lancing device by setting the needle depth in advance. It should be such that after the prick you need very light pressure to get enough blood. It should not be too deep or superficial.

Place the drop of blood at the indicated location on the test strip and wait for an audible or screen indication to confirm the sample.

After a few seconds, your blood sugar level will appear on the display. According to our standards, the value should be in mmol / L, but there are often glucometers that are imported from abroad and measured in mg / dL. In this case, the values ​​that will appear on the display will be very high. Approximately 100 mg / dL, which is equivalent to 5.55 mmol / L. In fact, the conversion is very simple.


The most common inaccuracies in the results are actually caused by incorrect measurement and not by a problem in the meter. The next time you conclude that your meter is not measuring correctly, first do a self-analysis of the measurement steps. You will be amazed at how accurate your meter is.

However, before taking your blood glucose meter and taking any action on your blood sugar level, please consult your doctor.

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