Diabetes (type 1 and type 2) in children and young people: diagnosis and management

Checking your blood glucose

You should be offered a real-time continuous glucose monitor (rtCGM) so that you can be aware of your blood glucose level at any time. You and your diabetes team should choose a device together, based on your preferences and needs.

You should be offered an intermittent-scanning continuous blood glucose monitor (isCGM, also called 'flash') if you cannot use rtCGM, or if you prefer isCGM.

Both types of continuous glucose monitor work with a sensor that you wear on your skin, and a display monitor or smartphone that shows your blood glucose level. rtCGM devices automatically send regular readings to the monitor or smartphone. You need to scan isCGM devices yourself.

If you cannot or do not want to use rtCGM or isCGM, you should be offered finger-prick testing to check your blood glucose levels. To do this, you prick your finger to get a drop of blood. You put this blood onto a meter strip, insert the strip into a testing meter, and it tells you your blood glucose levels. If you are using finger-prick testing, it's important to check your blood glucose at least 5 times every day. Sometimes you may need to check it more often (for example, if you are ill, playing sports or doing other exercise, or will be driving that day).

Even if you use continuous glucose monitoring, you will need to do finger-prick tests from time to time (for example, to check that your monitor is accurate). Your diabetes team will explain when you need to do finger-prick tests.

Your diabetes team will show you how to use the device or devices that you choose, and they will make sure you have enough testing strips.

Younger children can find out more about checking blood glucose on the Diabetes UK website.

Getting your blood glucose to the right level

Your diabetes team will help you manage your diabetes and get your blood glucose to the right level. They will help you decide:

Blood glucose is measured in mmol/litre (this means the millimoles of glucose in every litre of your blood). Millimoles are a unit of measurement, like litres or metres.

It's best to try to get your blood glucose to the level it would be if you did not have diabetes. This stops you getting problems like hypos, or problems that diabetes could cause you in the future (such as eye damage or gum disease). If possible, you should aim to get your blood glucose to these levels:

You and your diabetes team will agree what level of blood glucose is best for you (your target level). Your target level might be the levels written above, or it might be higher than this. Your diabetes team should help you decide a target level that does not cause you problems (such as hypos), and help you reach it.

HbA1c

Your blood glucose levels tell you how much glucose is in your blood right now. HbA1c (also called 'glycated haemoglobin') tells you the average amount of glucose that has been in your blood for the last 2 or 3 months.

HbA1c is measured in mmol/mol (millimoles per mole). Millimoles and moles are units of measurement, like litres or metres. HbA1c is also sometimes written as a percentage (for example, 6.5%).

Like with blood glucose, it's best to have an HbA1c level that's as close as possible to the level it would be if you did not have diabetes. This level is 48 mmol/mol or less (this is the same as 6.5% or less). Keeping your HbA1c level under control means you're less likely to get other problems caused by diabetes. Your diabetes team should help you decide a target level that does not cause you problems (such as a lot of hypos), and help you reach it.

Your diabetes team should check your HbA1c level 4 times a year. They do this with a finger‑prick test. If you are having problems with your blood glucose levels, they may check your HbA1c level more often.

When you start injecting insulin for the first time, you may find that you only need a small amount to keep your HbA1c at the right level. This is called a 'honeymoon period'. Over time, you will find that you need more insulin to control your diabetes.