Shipping Policy

Libre Life Banner Advert
Libre Life Banner Advert

Getting to terms with the Libre sensor

  • 4 min read

Getting to terms with the Libre sensor

These are some of the terms you will see mentioned in relation to diabetes management and use of the FreeStyle Libre sensor.

Ambulatory Glucose Profile (AGP) A chart shown on the reader (or smartphone) that provides a snapshot of glucose levels, trends and patterns.


Slow acting insulin.


Blood glucose or blood sugar. The measurement of glucose circulating in the blood.


Beta Cell Education Resources for Training in Insulin and Eating. A course led by a DSN that introduces type 1 diabetics to how to manage their insulin doses in relation to carbohydrate intake. Often a pre-cursor to being prescribed a Libre. An alternative to DAFNE (see below)


Term used when needle hits a capillary and blood spouts out of the middle of the sensor. Many users report that “bleeders are the best readers”.


Fast acting insulin.

Carb Counting

A way to counting the carbohydrates in a meal, which can then be matched with insulin dose. Improves control of glucose levels.


Clinical Commissioning Group. In the UK each area is divided up regionally and a CCG has responsibility for allocating funding in that area. Criteria for being prescribed the Libre may vary (within guidelines) depending on the CCG.


Continuous Glucose Monitor. A device that takes readings of blood glucose continuously.

compression low

A low reading that is usually due to pressure applied to the sensor site, having the effect of pushing interstitial fluid away from the sensor. It typically occurs whilst asleep and may be a cause of unreliable readings or no readings at all (with gaps on the graph).


Dose Adjusting For Normal Eating. It’s a way of managing Type 1 diabetes and providing type 1 diabetics with the skills necessary to estimate the carbohydrate in each meal and to inject the right dose of insulin. An alternative to BERTIE (see above).

dawn phenomenon

When the body is unable to match the early-morning rise in blood glucose which usually happens between 3 a.m. and 8 a.m. [It may be easier to identify with the Libre.]


A friend of a T1D that is also T1D.


The anniversary of the date that a T1D is diagnosed with diabetes.


Diabetic Specialist Nurse.

flash glucose monitor

A small sensor that you wear just under your skin. It records glucose levels continuously and you can find out your levels by scanning the sensor whenever you want to. However, there are no alarms as readings are only provided when you scan.


Scientific shorthand for Glycosylated Haemoglobin. measures average blood glucose levels over the previous 3 months.

honeymoon period

 The period of time following diabetes diagnosis when the pancreas is still able to produce a significant enough amount of insulin to reduce insulin needs and aid blood glucose control.


Hypoglycaemia. Low glucose level.


Hyperglycaemia. High glucose level.

interstitial fluid (ISF)

A thin layer of fluid that surrounds the cells of the tissues below the skin, The Libre sensor takes readings from here, not from the blood and hence there is a 5 to 10 minute delay in ISF glucose response to changes in blood glucose.

Libre Academy

A resource to support use of the FreeStyle Libre system provided in ‘bite-size’ modules which help with management of diabetes using the sensor.


Cloud-based software that collates information from the Libre reader or device used for scanning the Libre sensor. Enables you and health professionals to identify trends and patterns and produce reports showing personal diabetes management.


An app that enables the user to scan the sensor with a reader and/or smartphone.


Mean Absolute Relative Difference which is the difference between CGM and fingerstick test of glucose level.


A transmitter that can be attached on top of the Freestyle Libre that continuously reads the Freestyle Libre and sends the data to your phone. Turns the Libre into a CGM.


The wireless communication technology that enables a FreeStyle Libre sensor to transmit data to another device.

(CGM) rollercoaster

 The highs and lows of life with diabetes. Also referred to in relation to the lag with readings on the Libre (interstitial fluid) and fingerpick test (blood glucose).

Sick day rules

Sick day rules are provided by a healthcare professional to provide information on how to adjust insulin dosage to take into account illness and higher blood glucose levels.

Skin Tac

An adhesive barrier that prepares the skin for application of the sensor.

Triangle of Diabetes Care

 Refers to 3 aims of:

1.     Improving HbA1c;

2.     Reducing the frequency of hypoglycaemia;

3.     Limiting glucose variability (swings between high and low glucose).


A transparent medical dressing. can be used to cover and protect the sensor.


Type 1 diabetic.

unicorn A perfect 100% (within range) on the reader. Another type of unicorn can happen when the Libre and a BG meter display the same number.

warm up period

The wait time between the time you activate a sensor and the time can get readings on the receiver.



This article is the author’s own view and is not intended to be medical advice. You should always seek individual advice from your health professional. There is no endorsement of the product, FreeStyle Libre[1] or Abbott. The author is a type 1 diabetic and user of the FreeStyle Libre 1 which is funded by the NHS.

[1] FreeStyle Libre is a registered trademark of Abbott Diabetes Care Inc.

Leave a comment (all fields required). Please note, we are unable to respond to individual comments posted here.

Comments will be approved before showing up.