Continuous glucose monitors

• A sensor on the arm or tummy senses glucose in the fluid under the skin.
• Real-time monitors send readings to a phone or receiver every few minutes; flash monitors, such as FreeStyle Libre 2, need scanning.
• Readings can trail blood glucose by up to 15 minutes, Diabetes UK says.

Source: NHS, Diabetes UK

• Diabetes UK says people who do not qualify for an NHS device can self-fund.
• It says sensors are usually fine in the bath, shower and during sport.
• CGMs can be bought without a prescription from pharmacies, supermarkets and online, Bolt Pharmacy reports.
• Bolt Pharmacy says a CGM cannot diagnose diabetes, and consistently high readings warrant a GP visit.

Source: Diabetes UK, Bolt Pharmacy

• Real-time or flash, and which sensors it takes: each sensor is specific to its CGM model (Diabetes UK).
• A UKCA or CE mark; CGMs are regulated as medical devices by the MHRA (Bolt Pharmacy).

Source: Diabetes UK, Bolt Pharmacy

• Diabetes UK says to use a finger-prick test if symptoms do not match the CGM reading.
• High-dose vitamin C and some other substances can affect certain sensors, Bolt Pharmacy says.
• Adverse reactions can be reported to the MHRA through the Yellow Card scheme.

Source: Diabetes UK, Bolt Pharmacy

Can anyone get a CGM on the NHS?

The NHS says CGM should be available to anyone with type 1 diabetes, and that some people with type 2 diabetes who take insulin and meet set criteria should be offered a flash monitor.

How long does a sensor last?

The NHS says a sensor is generally replaced every 7 to 14 days, depending on the type.

Do I still need finger-prick tests?

Yes, now and then: the NHS says particularly when you drive or have a hypo, and Diabetes UK says whenever symptoms do not match the reading.

• Continuous glucose monitoring (CGM), NHS
• Flash and continuous glucose monitoring, Diabetes UK
• OTC continuous glucose monitors - UK guide, Bolt Pharmacy