Monitoring your blood glucose Aroturukitanga kūhuka ā-toto
For many people with diabetes, monitoring blood glucose (sugar) levels is essential for managing their condition. You can check your levels using a finger prick test and glucose meter, or use a continuous glucose monitor (CGM).
Ways to test your blood glucose
Finger prick test
The most common way to check your blood glucose (sugar) level is by a finger prick test and blood glucose meter. This involves pricking a fingertip to get a tiny blood sample and using a meter to measure the glucose level. It shows your blood glucose level at the time you test it.
You can watch a video that shows you step by step how to do a finger prick test.
Testing Blood Glucose — CareSens on YouTubeexternal link
Continuous glucose monitoring (CGM)
CGM is an alternative to finger-prick tests. CGM uses sensors that are inserted into the fatty layer under your skin that can detect your blood glucose levels. It has a transmitter that constantly sends data to a receiver, a compatible insulin pump, or smart device (phone or tablet).
A CGM can clearly show patterns and trends in your glucose levels. But it is important to check your glucose levels by using finger-prick tests if:
- your symptoms do not match the sensor readings
- you have any other concerns about the reading.
CGM allows you to set alarms for high and low glucose levels.
CGM is funded for some people with diabetes, but not for those with type 2 diabetes. Find more information about types of monitors and funding on Healthify.
When to check your blood glucose level
How often and when you test your blood glucose levels depends on:
- the type of diabetes you have
- how it is being treated
- how well controlled and stable your diabetes is.
Type 2 diabetes
If you are treating your diabetes with diet and exercise or diet, exercise and metformin
When to test:
- If your diabetes and lifestyle are stable, you might not need to test.
- If you do need to test, test before breakfast and 2 hours after meals.
If you are taking metformin, PHARMAC subsidises one box of 50 testing strips with each prescription.
If you are treating your diabetes with diet, exercise and sulphonylurea
- Test before breakfast and 2 hours after meals.
- Test 1 to 3 days a week .
If you are treating your diabetes with diet, exercise and insulin
- Test before meals and at bedtime.
- Test 2 to 3 days a week .
People with type 2 diabetes who need to test should get into a regular pattern of testing at least 2 to 3 days a week. This helps it to become a habit for you. If you want to test more often, that is OK.
If you are not testing every day, you should change to at least daily testing if you:
- are starting new treatment
- have unstable blood glucose
- have symptoms of high or low blood glucose
- are changing treatment
- are sick
- have major changes to your daily routine
- work as a driver.
Type 1 diabetes
If you are using Humalog, NovoRapid or Apidra with meals, or if you are on intermediate or long-acting insulin once or twice daily:
- test before meals
- 2 hours after meals
- at bedtime.
Most people get the best control of their diabetes if they test every day and adjust their insulin dose according to each test result.
If you do not test and adjust your insulin every day, you can identify patterns and make dose adjustments by testing at least 2 days a week.
Food and activity record
Your healthcare provider or dietitian may ask you to keep a food and activity record. This will help them check that your food choices are right for you and your level of activity.