Blood Sugar Level Ranges
Understanding blood glucose level ranges is key to both diabetes diagnosis and diabetes self-management.
This page states 'normal' blood sugar ranges and blood sugar ranges for adults and children with type 1 diabetes, type 2 diabetes and blood sugar ranges to determine people with diabetes.
If a person with diabetes has a meter, test strips and is testing, it's important to know what the blood glucose level means.
Recommended blood glucose levels have a degree of interpretation for every individual and you should discuss this with your healthcare team.
In addition, women may be set target blood sugar levels during pregnancy.
The following ranges are guidelines provided by the National Institute for Clinical Excellence (NICE) but each individual’s target range should be agreed by their doctor or diabetic consultant.
Recommended target blood glucose level ranges
The NICE recommended target blood glucose levels are stated below for adults with type 1 diabetes, type 2 diabetes and children with type 1 diabetes.
|2 hours after meals
|Non-diabetic||4.0 to 5.9 mmol/L||under 7.8 mmol/L|
|Type 2 diabetes||4 to 7 mmol/L||under 8.5 mmol/L|
|Type 1 diabetes||4 to 7 mmol/L||under 9 mmol/L|
|Children w/ type 1 diabetes||4 to 8 mmol/L||under 10 mmol/L|
NB: There are differing opinions about the ideal blood glucose level range.
You should discuss your own individual needs with your healthcare team.
Normal and diabetic blood sugar ranges
For the majority of healthy individuals, normal blood sugar levels are as follows:
- Normal blood glucose level in humans is about 4 mM (4 mmol/L or 72 mg/dL)
- When operating normally the body restores blood sugar levels to a range of 4.4 to 6.1 mmol/L (82 to 110 mg/dL)
- Shortly after a meal the blood glucose level may rise temporarily up to 7.8 mmol/L (140 mg/dL)
For people with diabetes, blood sugar level targets are as follows:
- Before meals: 4 to 7 mmol/L for people with type 1 or type 2
- After meals: under 9 mmol/L for people with type 1 and 8.5mmol/L for people with type 2
As is visible from the NICE targets, children with type 1 diabetes have a greater upper limit for their blood sugar levels by 1mmol/L.
There are two types of blood sugar levels that may be measured. The first is the blood glucose level we get from doing finger prick blood glucose tests. These give us a reading of how high our levels are at that very point in time.
The second is the HbA1c reading, which gives a good idea of our average control over a period of 2 to 3 months. The target blood glucose levels vary a little bit depending on your type of diabetes and between adults and children.
Where possible, try to achieve levels of between 4 and 7 mmol/L before meals and under 8.5 mmol/L after meals. The target level for HbA1c is under 48 mmol/mol (or 6.5% in the old units).
Research has shown that high blood glucose levels over time can lead to organ and circulation damage.
By monitoring blood glucose levels, we can spot when sugar levels are running high and can then take appropriate action to reduce them.
Keeping blood glucose above 4 mmol/l for people on insulin or certain medications for type 2 diabetes is important to prevent hypos occurring, which can be dangerous.
Your doctor may give you different targets. Children, older people and those at particular risk of hypoglycemia may be given wider targets.
How are blood sugar level ranges used to diagnose diabetes?
There are 2 main tests which are conducted to determine whether someone has diabetes.
Impaired fasting glycemia test
When being tested for diabetes by a impaired fasting glycemia test, blood sugar levels will normally be taken after around eight hours of fasting.
During this blood sugar levels are put into the following categories:
- Normal: 4.0 to 5.9 mmol/l (70 to 107 mg/dl)
- Prediabetes or Impaired Glucose Glycemia: 6.0 to 6.9 mmol/l (108 to 126 mg/dl)
- Diagnosis of diabetes: more than 6.9 mmol/l (126 mg/dl)
Impaired glucose tolerance test
An impaired glucose tolerance test involves taking a concentrated amount of glucose and then measuring blood sugar levels after two hours.
Impaired glucose tolerance or diabetes is diagnosed as follows:
- Normal: under 7.8 mmol/l (140 mg/dl)
- Prediabetes or Impaired Glucose Tolerance: 7.9 to 11.1 mmol/l (141 to 200 mg/dl)
- Diagnosis of diabetes: more than 11.1 mmol/l (200 mg/dl)
Why are good blood sugar levels important?
It is important that you control your blood glucose levels as well as you can as too high sugar levels for long periods of time increases the risk of diabetes complications developing.
Diabetes complications are health problems which include:
This list of problems may look scary but the main point to note is that the risk of these problems can be minimised through good blood glucose level control. Small improvements can make a big difference if you stay dedicated and maintain those improvements over most days.