Oh no, numbers!
Understand the different metrics used to measure blood glucose.
A brief introduction to the different metrics
How many different measurements you encounter depends on what tests you take, and how much time you spend online.
In the UK, the HbA1C is measured in mmol/mol. I am not going to try and explain what a mmol or a mol actually is. It's something to do with quantities of things within blood, and right now I feel that's all I need to know. This is the key number: it's used for diagnosis, and at your checkups.
If you also do fingerprick tests at home, you will encounter another unit of measurement. In the UK, this is usually mmol/L.
However, if you read up about diabetes online, or join web communities, you will frequently encounter the measurements used in the USA. For HbA1C, this is often given as a percentage (%), and for fingerprick tests, it is measured as mg/dL. The percentage unit for HbA1c was also used in the UK in the past, so if looking at older UK resources, you may encounter percentages.
Confused yet? Here are some resources to help with conversions:
| Link | Description |
|---|---|
| DiabetesChart - mmol/mol to mmol/L | UK metrics. This is useful if you want to see what your likely HbA1C will be, based on your fingerprick tests. Don't expect this to be precise: fingerprick tests have a fairly wide accuracy range. |
| Diabetes.co.uk - mg/dL to mmol/L | Convert between USA and UK fingerprick test results. |
| Diabetes UK - % to mmol/mol | Convert between USA and UK HbA1C test results. |
Healthy ranges and targets
Target averages
| HbA1C mmol/mol | Description | Approximate mmol/L |
|---|---|---|
| Below 42 | This is the normal, healthy number. | Below 6.8 |
| 42-48 | Pre-diabetic. This is the NHS target range for people with type 2 diabetes. | 6.8 - 7.8 |
| Above 48 | Diabetic. Ideally, you should manage your diabetes well enough to stay below this number | Above 7.8 |
Source: Diabetes UK - HbA1C.
Note
The HbA1C is an average of your blood glucose over three months, while fingerprick tests give a snapshot of a specific moment. You don't need to always stay in range with the fingerprick tests. It's likely you will sometimes be higher, sometimes lower.
Fingerprick test targets
Target fingerprick test results for type 2 diabetics.
| Conditions | Fingerprick in mmol/L |
|---|---|
| Fasting (A fasting test is taken when you wake up, before you eat anything) | 4.0 - 7.0 |
| Two hours after a meal | 4.0 - 8.5 |
Source: Diabetes UK - Testing.