Diagnosis of Diabetes
Following suspicion that the patient may be suffering from diabetes because of symptoms or the presence of complications, tests will be done to measure the level of sugar in the blood (blood glucose).
The blood testing can be:
1. Random
2. Fasting (that is, after an overnight fast)
3. Following a glucose tolerance test (GTT)
Random
On random blood glucose testing (which is done on 2 occasions): -
- Any figure above or equal to 11.1 mmol/litre is diagnostic of diabetes
Fasting
The blood glucose level is tested on two different days: -
- Normal fasting blood glucose is less than 6.1 mmol/litre.
- A reading above or equal to 7.0 mmol/litre is diagnostic of diabetes
Oral Glucose Tolerance Test (OGTT)
This is done when the results are unclear from the above tests. After an overnight fast, a glucose drink is given, which contains 75gram of glucose. The blood is tested before the drink and 2 hours after: -
- A normal blood level is below 7.8 mmol/litre
- A blood level at or above 11.1 mmol/litre is diagnostic of diabetes
