People with diabetes often have to test their blood sugar levels up to multiple times per day, but blood glucose meters can sometimes display inaccurate readings.

At the time, you may not realise that readings could be wrong. This could then affect your treatment regimen and potentially cause you problems, especially if you inject insulin when your blood glucose meter displays an erroneous high reading.

Of course, modern meters have evolved so inaccurate readings are much less common, but it is still important to be aware of why false readings can occur.

Here are five factors to bear in mind when testing your blood sugar.

1. Sugary substances on your fingers

Even the slightest bit of sugar on your fingers can ramp up your test result. But this also goes for bits of dirt and traces of other food that may still be on your fingertips. Make sure you wash your hands before each test to ensure the most accurate result.

2. Wet fingers

Once you’ve washed your hands, make sure they are thoroughly dry before testing. If a blood drop becomes mixed with water it can dilute the sample, causing an inaccurate reading.

3. Expired test strips

All test strips have an expiry date. If you use a test strip which is out of date then it can lead to faulty results. Make sure you know the expiration date of your strips. If your test strip is out of date, do not use it, as the result cannot be trusted.

4. Extreme temperatures

Extreme temperatures can have a big impact on blood glucose meters. Meters should state their specific temperature ranges, and testing outside of this range can affect test results.

If a meter is too cold it tends to produce inaccurately low readings, and hot meters inaccurately high readings.

If it’s a very cold day, test your blood indoors, where it’s warmer. If it’s a very hot day, try to test your blood in the shade.

Furthermore, make sure that your test strips at kept at room temperature, in a cool dry place. If the strips are exposed to sunlight or kept outside their original container, it can affect their functionality.

5. Meter not calibrated

It’s recommended to calibrate your meter on a regular basis. This can help stop your meter losing its accuracy without any obvious warning signs.

Consult your meter’s instructions manual to find out how to calibrate your specific meter. It is recommended to do this monthly, but you should also calibrate it if you suspect your meter is providing inaccurate results.