A blood sugar test measures the amount of a sugar called glucose in a sample of your blood.
Blood sugar test is done in various ways, which divided into 4 types:
- Fasting blood sugar (FBS)
To measure level of blood sugar, you should not to eat and drink, 10- 12 hours before test, because they can stimulate digestive and muscular system and changes result of the test. You can resume your diet, immediately after testing.
Interpretation of the result
Normal level of sugar is between 65 to 70 mg/dl. 100- 110 mg/dl is the highest level. Sometimes this increased level is temporary and is due to consuming sugar food and it’s better to repeat testing.
Level of sugar more than 400, or less than 60, is dangerous, and is marked. Sugar less than 30 and more than 300, in babies, is dangerous.
- 2- hour blood sugar test
This test is done 2 hours after eating, and is a valuable test for screening diabetes, evaluating response to treatment and monitoring medications in diabetes patients. In patients who have problem or disease, this type of sugar shows abnormalities.
Don’t drink and eat, 10- 12 hours before testing. After first testing, eat your breakfast as usual. This test should be done exactly 2 hours after the first test, less or more than this time, affects on result of the test.
Avoid using medications that reduce your blood pressure.
Using acetaminophen before testing, shows false positive result. So, it’s better to inform your doctor about any drug usage.
- Oral glucose tolerance test (OGTT)
This test is done in diabetes person and those who have glucose under 140 mg/dl. So, it can be affected by diet and diseases. This test may take about 3- 6 hours.
Avoid smoking 3 days before testing.
Have a carbohydrate diet, 3 days before testing.
Refer to laboratory in the morning.
First, blood and urine test is taken, then you should eat a syrup contains 50 to 100 gr glucose, after eating you may feel weakness, vertigo and anxiety. But these symptoms are temporary and will be faded on its own.
- Glucose challenge test (GCT)
This test is done to screen women who have mellitus diabetes during their pregnancy. Urine test or urinalysis is tested to determine sugar level.
This test lasts about 90 minutes.
You can eat food 2 hours before testing.
A glucose syrup is taken to you.