Glucose testing can indicate how well the body is utilizing blood glucose if it has been diagnosed with diabetes or if the doctor has a high suspicion that it may have the disease.
Sometimes it is necessary to test for fasting blood glucose. This means that no food (other than water) is consumed for a certain amount of time before the blood sample is taken. The purpose of this is to make sure that all the food that has been consumed has been digested, but not all blood glucose tests need to be done on an empty stomach.
Fast blood test
Fast blood glucose test
Doctors often use this test to diagnose diabetes. Your doctor will tell you to fast for 8 hours before the test. Therefore, the test is usually scheduled early in the morning so that you don’t have to fast for a long time. A blood glucose level of 126 mg/dL or higher is highly suspicious of diabetes. In healthy people, this value is less than 100 mg/dL.
Oral glucose tolerance test
This is another test that is used for diagnosis. It also requires an 8-hour fast before the test. The nurse takes a blood sample to start the test. After 2 hours, the nurse will take another blood sample for testing. If the test results indicate a blood glucose level at or above 200 mg/dL, diabetes will be diagnosed. If the blood glucose level is between 140 and 199 mg/dL, the person is pre-diabetic. This suggests that the blood sugar is higher than normal but may not progress to diabetes if certain lifestyle changes are made.
This test is also used in the diagnosis of gestational diabetes. Gestational diabetes is when a woman develops or is diagnosed with diabetes only during pregnancy. The test is the same, the only difference is that the nurse will take a 3rd blood sample 3 hours later.
Non-fasting blood test
Random blood glucose test
Doctors often use this test to diagnose patients with severe diabetes symptoms and to check current blood glucose levels at any time. Therefore, there is no need to fast before collecting a blood sample. If a blood glucose level of 200 mg/dL or higher is detected, diabetes is highly suspected.
Oral glucose tolerance test
Most pregnant women will have this test between 24 and 28 weeks of pregnancy to check for gestational diabetes. Your doctor will also order you to drink a sugary liquid and wait in the waiting area of the exam room for 1 hour to take a blood sample. The test does not require fasting and can be done at any time of the day.
If the result is at or above 130 mg/dL, the doctor may order another test to confirm gestational diabetes on another day.
Glycosylated hemoglobin (HbA1c) test
The results of the HbA1c test can be used to evaluate glycemic control over the past 3 months, which means that it does not matter if you have fasted before the test. The results are expressed as a percentage. The higher the percentage, the higher the average blood glucose level.
If your blood glucose level is at or above 6.5%, you may have diabetes. A normal person’s blood glucose level should be less than 5.7%. Once the diagnosis is clear, your doctor will use this test as a measure of recent changes in blood glucose levels. the target HbA1c level should be less than 7%.
Glucose meter
If you have diabetes, you can use this device to test your blood glucose levels at home. Your doctor will tell you how often you need to test and whether you should do it at a specific time. For example, it may be necessary to test blood glucose levels before a snack or meal. The blood glucose meter test does not need to be done on an empty stomach.