What’s the ‘right’ range of BGLs?

People with diabetes wage a daily battle against high blood glucose levels (BGLs).


Coupled with a healthy diet and exercise, maintaining BGLs in a recommended range is the key strategy necessary if you hope to reduce your risk of long-term complications, such as loss of vision, kidney or heart disease, or limb amputation.


On a daily basis, effective monitoring requires a handheld meter using a capillary (small vessel) blood sample, usually from a finger prick. This is in addition to a three, six or 12 monthly measure of the HbA1c, or glycated haemoglobin.


In a person without diabetes, BGLs range between 4.0 - 7.8 millimoles of glucose per litre of blood (mmols/L) throughout the day, regardless of how they eat or exercise, or what stress they're under. 


But living with diabetes means your body cannot regulate blood glucose automatically. Keeping blood glucose in this range is often difficult and sometimes dangerous when hypoglycaemia (a hypo) can be just a mmol/L away.


Each person with diabetes is provided their own targets by their GP or specialist. However, we can assist by providing some general guidance.


Regular monitoring of BGLs using a handheld meter:


Type 1 Diabetes

Target Blood Glucose Levels

  • Before meals: 4 to 6mmol/L
  • 2 hours after starting meals: 4 to 8mmol/L


Type 2 Diabetes

Target Blood Glucose Levels

  • Before Meals: 6 to 8mmol/L
  • 2 hours after starting meals: 6 to 10mmol/L 



A BGL below 4mmol/L can lead to the uncomfortable and sometimes dangerous symptoms of a hypo. 

A BGL of over 15mmols/L  can make you feel unwell,  tired, increase your thirst and send you off to the toilet to pass urine frequently. This is called hyperglycaemia and action needs to be taken to bring levels back to your target range.


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An occasional BGL over 10mmol/L is not considered too serious for most people with diabetes but if blood glucose continues too high for too long it increases HbA1c (see below) .


In a person with type 1 diabetes, high blood glucose levels can lead to ketones in the blood (ketosis)  which can be dangerous if not treated promptly. 


The big picture on blood glucose

HbA1c, or glycated haemoglobin, is a measure, on average, of blood glucose over the previous two to three months taken at a pathology lab from venous blood.


HbA1c is an important complement to your ongoing home monitoring regime because it reveals an overall picture of blood glucose levels. Consistently high BGL levels will lead to high HbA1c averages, even if elevated levels were not apparent in BGLs you recorded on your hand held metre in testing during the relevant period.


The general recommended HbA1c is equal to or less than 53mmol/mol or 7%.

However, in 2009 the Australian Diabetes Society recommended individualised targets for adults with diabetes including:

  • For people without known cardiovascular disease, have not had diabetes a long time and do not experience severe hypos or another contraindication, the HbA1c target is equal to or less than 48 millimoles per mol (6.5%).
  • For people who do not feel the symptoms of hypos and do not know that their BGLs are dropping (hypo unawareness) or if they have other major health conditions, the target may increase to 64 mmol/mol (8%).
  • For women planning a pregnancy, the aim is for preferably equal to or less than 42mmol/mol (6%) before and during pregnancy but must avoid severe hypoglycaemia.
  • For people nearing the end of their life the most important thing is that they are as comfortable and free from the symptoms of high or low blood glucose levels as possible.



All doctors caring for people with diabetes should look at each person individually and make recommendations taking into consideration people on insulin or sulphonylureas who may need higher targets to prevent hypoglycaemia.


This is particularly relevant for the elderly, those at risk of severe hypoglycaemia, and those affected by hypoglycaemic unawareness.


If you don't know what your individual targets are ask your GP or specialist.


If you want to know anything more about measuring your BGL talk to your diabetes educator or call our Helpline on 1800 177 055 to speak to one of our Diabetes Queensland Health Professionals.


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