Skip to main content

Continuous glucose monitoring (CGMs)

You can check your sugar levels at any time with a continuous glucose monitor (CGM).

It lets you see patterns in your levels and sends you an alert if your sugar (glucose) is too high or low.

If your blood glucose reading is:

A CGM is made up of:

  • a sensor – a small device you attach to your tummy that senses how much sugar is in the fluid under your skin, called interstitial fluid
  • a transmitter – attached to the sensor, which sends results to a receiver, or mobile phone

You can either see your blood sugar levels on a receiver, which is a small box that displays the results, or on your mobile phone.

Some CGMs are integrated and you can see your sugar levels on the pump.

You generally need to replace a sensor every 7 days. Some models can be worn for several months.

Interstitial fluid sugar readings are a few minutes behind your blood sugar levels. This means you'll still need to do finger-prick checks every now and then.

To get the best out of a CGM, you'll need to look at the information it gives you with your team.

How to get continuous glucose monitoring (CGM)

You can buy a CGM yourself

As a rough guide, it costs around:

  • £1,000 for a monitor that does not need a pump
  • £500 for a monitor that works with an insulin pump
  • £40 to £60 for sensors

You do not have to pay VAT on blood glucose monitors:

Getting a CGM on the NHS

Flash glucose monitoring should be available on the NHS to anyone who meets certain criteria. This includes if you have type 1 diabetes and you're pregnant.

You can find the NHS flash criteria you need to meet on Diabetes UK

In some areas, it might be available to people who do not meet this criteria.

Ask your diabetes team about getting flash glucose monitoring.

Borrowing a CGM

Some clinics lend CGMs for a short time to help people look for patterns in their blood glucose levels if they're struggling.

Ask your diabetes team if they can do this. You might have to wait if it's already on loan.

Learn more about CGMs on the JDRF website

Page last reviewed: 6 July 2021
Next review due: 6 July 2024