Blood glucose and blood sugar are interchangeable terms, and both are crucial to the health of the body; especially for people with diabetes.
Most diabetics will be familiar with the terms blood glucose, blood glucose test, blood glucose level and blood glucose meter, but what does blood glucose really mean? Why do blood sugar levels need to be controlled?
What are blood glucose levels?
Blood sugar levels are literally the amount of glucose in the blood, sometimes called the serum glucose level. Usually, this amount is expressed as millimoles per litre (mmol/l) and stay stable amongst people without diabetes at around 4-8mmol/L.
Spikes in blood sugar will occur following meals, and levels will usually be at their lowest in the early mornings.
When it comes to people with diabetes, blood sugar fluctuates more widely.
Blood glucose guides
Read guides on blood glucose and related topics. The most read guides are currently:
- Blood glucose level ranges - blood glucose level recommendations according to the IDF
- Blood glucose meters - a comparison of the blood glucose meters available in the UK
- Blood glucose test strips - what test strips do and how you can get them (via the NHS or privately)
- Blood glucose diary - benefits of a recording your blood glucose levels + free diary download
- How to test your blood glucose - watch Ben show you how to test your blood glucose levels
- HbA1c - what HbA1c is and what HbA1c levels you should you be aiming for
- Ketones - what ketones are, how to spot them and what to do if you have ketones in your blood
Why do blood glucose levels need to be controlled?
High levels of glucose present in the blood over a sustained period of time end up damaging the blood vessels. Although this does not sound too serious, the list of resultant complications is.
The time-scale for the development of these complications is usually years, but be aware that type 2 diabetes is often not diagnosed until a relatively late stage.
How do I find out what my blood glucose levels are?
You can use home testing kits, although before doing so read our guide to blood glucose monitors.
Measure levels by putting a drop of blood on a strip and placing it into a BGM (blood glucose meter). Prick your finger with a specially designed lancet to draw blood.
Blood glucose is at the heart of diabetes. The reason we have been diagnosed with diabetes is because the level of blood glucose in our blood is higher than it should be.
When we eat foods with carbohydrate in, the food is broken down. The carbohydrates in the food are broken down into glucose which is then absorbed into the bloodstream and therefore raises our blood sugar levels.
The more carbohydrate we eat, the more glucose is absorbed into the blood. As the concentration of sugar in our blood rises, the body will try to send insulin to help store this sugar in our body’s cells where it can be used for energy.
In type 1 diabetes the body is unable to produce enough insulin to cope with the increase in blood sugar levels. To keep blood sugar levels at a healthy level, insulin needs to be injected or infused by an insulin pump.
In type 2 diabetes, insulin is less effective than in people without the condition. Because their insulin is less effective, people with type 2 diabetes will need to produce more insulin to cope with high blood sugar levels.
This often leaves the body struggling to produce enough insulin to bring down sugar levels quickly enough.
If you have blood glucose levels that are consistently on the high there are two main ways of tackling high levels.
- The first way is by taking an increased amount of insulin or medication that helps insulin work more effectively. Only make changes to your medication if it is agreed with your doctor.
- The second way is to reduce the amount of carbohydrate we eat.
- This can be a particularly effective way for people with type 2 diabetes.
Home blood glucose monitors are a straight forward way of measuring your blood sugar levels.
What is a good blood glucose level?
NICE guidelines for the UK currently recommend the following:
- A normal pre-prandial (before meal) blood glucose level will be between 4 and 7 mmol/l.
- After eating (post-prandial) levels should be below 9 mmol/l when tested 2 hours after a meal.
- When going to bed for the night, levels should be no more than 8 mmol/l.
When should blood glucose levels be measured?
The number of times per day blood glucose levels should be measured depends entirely on the diabetics. Type 1 diabetics using insulin should check their blood sugar levels before every meal, sometimes as often as five times per day.
For type 2 diabetics controlling their condition with diet, you should test several times a week.
However, this doesn't apply to everyone, and each individual case should seek expert advice.
Are there special times when blood glucose should be measured?
Any time you feel ill, and over time if you can feel your blood sugar becoming too low or too high, you should check your blood glucose levels.
You should also be aware that a reading over 20mmol/l should prompt a urine test for the presence of ketones.
What is an HbA1c test and how does it relate to blood glucose?
HbA1c tests show average blood glucose levels over a sustained period of time. HbA1c is glycated haemoglobin and more of it is produced in the body by high blood glucose levels.
Different scores of HbA1c show good, fair, poor and bad control of diabetes. Increasing HbA1c levels indicate greater risk of complications.