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Measuring blood sugar step by step

Blood sugar self-measurement is not technically complicated. All you need is the correct equipment, instructions on how to use the meter and finger-prick device as well as instructions on how to perform the check in a reliable way.

Video has English subtitles.

To check your blood sugar, you need a blood glucose meter and compatible strips as well as a personal lancing device with suitable lancets or a disposable lancet. There are different devices available, and different care providers use different models. You can acquire the blood glucose meter, strips and other equipment free of charge through your municipality’s care supplies distribution on the basis of a referral issued by your care provider.

You should consult your nurse regarding a lancing device and meter. Please read the user instructions of your blood glucose meter and strips carefully.

You can find suitable times for measurement from the article:

The threshold values for blood sugar in diagnosing diabetes can be found in the article:

Recommended blood sugar target levels for diabetes treatment can be found in the article:

 In the image is a blood glucose meter, a strip container, a lancet pen, and lancet needles in their own storage case.

Take out the equipment for measuring your blood sugar. Check the use-by date on the strip box. You should also find out the storage life of the strips after the box has been opened and mark the opening date on the box. Store the strips in the box or package, which is opened just before checking your blood sugar. This way you'll protect the strips from dirt, dust and humidity.

In the image are hands that are being dried with disposable paper towels.

If possible, wash and dry your hands. Do not use hand sanitiser as it may affect the result. Damp hands or dirt or food scraps on your fingers may affect the result. If the injection site is damp, it may make it harder to get a good drop of blood. The main thing is that the hands should be as clean and dry as possible.

In the picture, there are hands placing a green lancet into a lancet pen.

Lancing devices i.e. lancet pens and lancets come in many different models. There are also safety lancets available, which can only be used once.

It is good to check the lancet pen before measuring. Check the pricking depth and change the lancet needle, if necessary. You can achieve the correct drop size by adjusting the pricking depth. If the drop is too small, increase the depth of the prick.

In idividual use the same lancet can usually be used for one day before changing, unless otherwise instructed by your treatment centre.

In the picture, there are hands placing a green lancet into a lancet pen.

Handle the strip with clean, dry fingers. Put the test strip into the strip slot on the meter. The part of the strip which absorbs the drop of blood should be left visible. Correctly inserted, the strip turns the meter on. If the meter doesn't turn on when you insert the strip, check that the strip is the right way round. Any dirt or dust in the strip slot on the blood glucose meter may also cause a malfunction.

In the image, there is a blood glucose meter, a lancet pen, and hands holding a test strip, with a drop of blood gently squeezed out of the left index finger."

With a lancing device, you should obtain a drop of blood of the correct size without squeezing your fingertip. The drop of blood should be nearly the size of a peppercorn. If a drop does not form, you can gently squeeze the base of your finger or “milk” your finger. If the drop does not seem to form properly, you can try increasing the pricking depth of the lancing device. Check also "Make checking easier".

Wipe off the first drop of blood, if possible. This way you can reduce the risk of potential impurities in the sample. Let the next drop of blood of sufficient size absorb into the test area on the strip. This is especially important if you have not been able to wash your hands.

If you struggle to get a large enough drop of blood, you do not have to wipe off the first drop as long as the skin around the area is clean.

In the image, a lancet pen held in the right hand is about to be used to make a prick in the left hand's index finger.

The edges of fingertips are good test sites. However, right next to a fingernail is not a good place. The area is more sensitive, and it may result in paronychia or an infection of the skin around the fingernail. You should avoid pricking your thumbs and forefingers as they are more sensitive than the rest of the fingers and you use them a lot.

Ideally, keep the blood glucose meter and strip facing upwards, directly towards the drop. Let the drop of blood absorb into the strip. Normally, the result is displayed on the screen of the meter in a few seconds. If the result is not displayed, the meter will show an error code. If the result seems suspicious and does not fit what you are feeling, you should perform the test again using a new strip.

Finally, remove the strip from the meter and discard it.

All the error codes for the meter and their explanations can be found in the meter's user manual. That's the first place to check for the potential cause of an error. One of the most common reasons for error codes during measurement is an insufficient amount of blood.

In the  image, hands are being cleaned and warmed under running water.

You can make the checking easier by washing your hands in warm water and rubbing them in order to warm up the test site. You can keep your hand pointed down for a minute, make a fist or shake your hand. If you are unable to obtain a decent drop of blood, check the pricking depth of the lancet. Use as many different test sites as possible and keep changing the test site on a regular basis. It is important to take care of the skin of your hands by moisturising them in the evenings, but not before a test.

Usually, you get used to the pain caused by the prick. It may depend on the pricking depth and lancet model. Your nurse can advise you regarding the choice of lancing device and test device.

Make sure to discard the used equipment properly. Used lancet pen lancets are sharps waste, which means that you should cover the needle tip before placing the needle in the bin. Alternatively, you can place the needles inside a plastic bottle, for example. Test strips are mixed waste, the batteries of the blood sugar meter are hazardous waste, and discarded meters are electronic waste.

Updated 30.9.2023