Last Updated on March 28, 2025 by Analgesia team
Capillary blood glucose (CBG)
Capillary blood glucose (CBG) tests are Blood glucose level (BGL) or Blood sugar level (BSL) monitoring conducted outside of clinical facilities, such as at home. They can also be referred to as self-monitoring blood glucose (SMBG).
CBG is important for diabetics to monitor their blood sugar, which helps determine if they are meeting their glucose targets. This helps them reduce the unpleasant symptoms of high and low blood sugar and avoid long-term diabetes complications.
What is a normal CBG level in the UK?
The target range for blood glucose level is 4 to 7mmol/l. If the blood glucose falls below this, hypo symptoms usually occur. However, over 8mmol/l, there may not be any symptoms at all.
When should I test my CBG?
Often, testing is advised before meals and at bedtime if you take more than one shot of insulin a day. You may need to test only before breakfast and sometimes before dinner or at bedtime if you use an intermediate- or a long-acting insulin.
Why it’s important
- CBG tests provide immediate information on blood sugar levels
- This information is important for managing diabetes and other metabolic disorders
- Unusually high or low blood sugar levels can be life-threatening
CBG was previously known as self-monitoring of blood glucose (SMBG)