CGM education

CGM basics: from snapshots to the full curve

A blood glucose test records one moment. A continuous glucose monitor records a series of sensor glucose values. This page explains what that series can show, what the sensor measures, and what it cannot decide.

The same day, two ways of seeing it

Four honest readings, and everything between them is guesswork: the rises after meals and the overnight drift are invisible.

Illustrative shape only: not a real recording, not a target, and no clinical values are implied.

Where the reading comes from

The filament reads glucose in the interstitial fluid just under the skin, which follows blood glucose with a short natural delay. That is why device instructions describe when to confirm a reading with a fingerstick.

What a CGM actually measures

A continuous glucose monitor uses a small wearable sensor with a flexible filament under the skin. The SIBIONICS GS1 is worn on the back of the upper arm. It measures glucose in interstitial fluid rather than directly in a blood vessel.

Interstitial and blood glucose are related but are not identical at every moment. The value on a CGM can differ from a blood glucose result, particularly while glucose is changing.

If a sensor reading does not match your symptoms or expectations, follow the current Instructions For Use on checking blood glucose and follow your care team's plan.

From isolated readings to a pattern

A blood glucose test records one moment. A CGM records a series of sensor glucose values. Official GS1 information describes a new reading every 5 minutes, a 1-hour warm-up, and up to 14 days of sensor wear.

The series can show recent direction and recurring patterns that isolated readings may miss. It still needs context from symptoms, meals, activity, medicine, device status, and the plan agreed with a clinician.

Who the product is intended for

Official SIBIONICS material describes the GS1 for people with diabetes, but age indications and other labeling details vary by country. The label and Instructions For Use supplied with the local product determine who may use it.

A clinician can help decide whether CGM is appropriate and how its data fits into care. This local information site does not extend the product indication to wellness, screening, prediabetes, pregnancy, or any other use.

A CGM monitors sensor glucose. It does not diagnose diabetes or replace laboratory testing and clinical review.

What a CGM does not tell you

A glucose sensor does not measure insulin, ketones, blood pressure, or long-term complications. It also cannot decide a medicine dose or explain why a value changed.

Official guidance says to use a blood glucose test when readings do not match symptoms or expectations. Device alerts, compatibility, wear, water exposure, imaging restrictions, and troubleshooting must follow the current country-specific label and Instructions For Use.

Never change medication or treatment from this page. Use your prescriber's plan and the instructions supplied with your device.

Go deeper

Ready for the next layer? Learn to read the arrows the app shows you, or walk through how a sensor is applied. For the wider science of everyday glucose, our sister site glucose.mu covers glycemic load, HbA1c, and more with its own interactive tools.

Reading your trend arrows Sensor application walkthrough

Medtech lists SIBIONICS among the manufacturers it represents in Mauritius. See the Medtech brands page and contact the local team to confirm current product availability. Involve your care team when deciding how CGM data fits into your care.

Sources

GS1 product information and support SIBIONICSOfficial specifications, safety notes, compatibility guidance, and country-specific labeling cautions.
CGM app guide SIBIONICSOfficial app and sensor guidance. The current product insert supplied locally remains authoritative.
Continuous glucose monitoring and flash monitoring NHSIndependent overview of CGM and the need to use readings within a care plan.

Last reviewed: 2026-07-18