Blood Glucose Monitoring

This article has been medically approved by Pharmacist Sumaiya Patel - GPhC Reg No: 2215078

For those who have diabetes, blood glucose testing is one of the main tools for monitoring blood glucose levels and is very helpful when making diet and medication dosing decisions. In our article below, we’ll look at what Blood Glucose Monitoring is and why it is important.

What is blood glucose?

Your blood sugar levels, also known as your blood glucose levels, is the amount of glucose that is in your blood. We get glucose from food and drink, and our body produces insulin to move this from the blood into the cells where it gets broken down to form energy. Your blood sugar levels naturally go up and down throughout the day, but for people living with diabetes, these changes can be bigger and more frequent.

A person with diabetes either lacks insulin and has to take insulin injections (type 1 diabetes) or is unable to use the insulin their body produces (type 2 diabetes). As a result, glucose levels in the blood get higher and higher instead of being converted into energy. Over time this can lead to serious organ damage, making it is essential to keep blood sugar levels as stable as possible.

Although diabetes is characterised by blood sugar levels becoming too high, insulin treatment can sometimes cause levels to drop too low. This is known as hypoglycaemia or hypo.

Testing your blood glucose

Monitoring your blood sugar levels is an important tool involved in controlling diabetes. You should also test your blood sugar levels if you take any medication that can lead to hypoglycaemia.

You can test your levels by doing a finger-prick test, using a flash glucose monitor, or with a continuous glucose monitor (CGM).

Blood glucose testing can help you to control your diabetes by assisting you in making informed choices about food and portion sizes, supporting decisions about medication dosing, and identifying periods of high or low blood glucose levels. This can lead to a reduction in glycated haemoglobin (HbA1c) levels, a lower risk of serious complications, reduced depressive symptoms, and improved confidence in diabetes self-management.

However, blood glucose testing also has some disadvantages like pain when pricking fingers, cost of testing supplies if these need to be self-funded, and worry about results if you don’t know what they mean.

Normal and diabetic blood sugar ranges

For most healthy individuals, normal blood sugar levels are:

• Between 4.0 to 5.4 mmol/L (72 to 99 mg/dL) when fasting
• Up to 7.8 mmol/L (140 mg/dL) 2 hours after eating

For people with diabetes, blood sugar level targets are:

• Before meals: 4 to 7 mmol/L for people with type 1 or type 2 diabetes
• After meals: under 9 mmol/L for people with type 1 diabetes and under 8.5mmol/L for people with type 2 diabetes

How often should I test my blood glucose?

People with type 1 diabetes should test their blood glucose at least four times a day, including before each meal and before bed. People with type 1 diabetes should also be supported by their GP to test more often if certain factors apply. These can include taking part in sport, ensuring safe driving, and if you have impaired hypo awareness.

People on medication that can cause hypoglycaemia should test their levels at least once a day. Aim to test at different times of day to see if blood glucose levels are going too low or too high at those times. This, in turn, can help you to prevent low or high results and can be done with support from your doctor. If you are on medication that can cause hypos, you should be prepared to test your blood glucose levels any time you feel the signs of a hypoglycaemic attack, even if you don’t test regularly.