Usually blood sugar levels are tested in the “fasting” state – when you have not had anything to eat or drink for eight hours. The normal range for fasting blood sugar is anything from 3.0 to 5.5 mmol/L. If you have not fasted, the normal range for random blood sugar is between 3.0 and 7.8 mmol/L.
The body can usually keep the blood sugar within this range despite variations in food intake and energy expenditure, but if the blood test is done very soon after eating, it is possible it may be slightly above.
Other conditions which may temporarily cause increased blood sugar readings include acute infection, trauma and physical or psychological stress.
In such cases the raised blood sugar may not be indicative of diabetes and the test should be repeated once the condition of circumstances have stabilised or resolved.
If your blood test was done immediately after eating a large amount of carbohydrates or if you had a concurrent health condition or circumstances such as those described above, this might explain the result being mildly above the range for random glucose.
But if your result of 8.0 was after fasting for eight hours this is very concerning as it could well indicate a diagnosis of diabetes.
If you did not fast for your last test, your doctor may advise you to repeat the test and fast this time and hopefully it will be in range (below 5.5 mmol/L). If your level of 8.0 was after fasting, your doctor may advise repeating the test (a fasting blood sugar that is repeatedly over 7.0 indicates a diagnosis of diabetes) and possibly doing a further test known as a glucose tolerance test (GTT).
With the GTT you have a baseline fasting blood sugar level done and then you are given a standard measured dose of a glucose drink to consume over five minutes. Your blood sugar level is taken again two hours later. The result should be less than 7.8. A result between 7.8 and 11.1 is indicative of “impaired glucose tolerance” and a result above 11.1 indicates a diagnosis of diabetes.
People diagnosed with impaired glucose tolerance are considered “prediabetic.”
