Traditionally, self-monitoring blood glucose (SMBG) devices have been used to test blood sugar (blood glucose) at home using glucose test strips to take a snapshot of your blood glucose levels at a single point in time.5 But you need to prick your finger and physically take several readings throughout the day.5
More recently, devices have been developed that allow real-time 24-hour monitoring of your blood glucose levels, called continuous glucose monitors (CGM).2,6 A CGM device takes your ‘interstitial’ glucose measurements using a small sensor attached to your body through a tiny wire just under the skin.
Interstitial glucose sounds complicated but all it means is that the monitor measures the sugar level in the fluid under your skin rather than directly from your blood.2 The sensor sends this information to a reader which then shows the numbers and stores all the data.2 A CGM device allows you to quickly check your glucose levels without having to do finger pricks, as they track your glucose levels continuously, around the clock. This gives you a more accurate understanding of your day-to-day fluctuations.6
The data from the CGM device is sent to your smartphone app or reader, providing useful insights to help you increase your understanding of your daily glucose patterns and manage your diabetes better. CGM devices can show you lots of different useful measures, including:6
- Current and average glucose levels
- How much your glucose levels vary (known as glycaemic variability)
- Trend arrows that show if your glucose levels are going up or down
- The amount of time you spend within, above, or below your target glucose range (known as Time in Range, Time Above Range and Time Below Range)
Download this free CGM Cheat Sheet which gives you the basics about starting with a CGM device