A blood glucose test measures the amount of glucose, a type of sugar, in your blood. Glucose is the bodys main source of energy, and a hormone called insulin helps move glucose from the blood into the cells where it can be used for energy. There are several reasons why a healthcare provider may order a blood glucose test, including:

• To screen for diabetes by measuring the level of glucose in your blood
• To monitor people who already have diabetes
• To diagnose and monitor prediabetes
• To investigate symptoms of high or low blood glucose levels

During a blood glucose test, a healthcare professional will take a blood sample from a vein in your arm using a small needle. For some types of glucose blood tests, you may be asked to drink a sugary liquid and wait for an hour before your blood sample is taken. The results of a blood glucose test can help diagnose diabetes, prediabetes, and other conditions related to blood glucose levels. A normal blood glucose level depends on the type of test, but generally, a level between 70 and 100 mg/dL is considered normal for a fasting blood glucose test.