The sugar in your blood, referred to as blood glucose, serves as the chief energy source for your body. In a healthy individual, the hormone insulin, which is released by the pancreas, allows your cells to use glucose, which controls the amount of glucose in the blood. Several different blood tests can measure the amount of glucose in your blood and determine if your blood sugar levels are healthy.
Fasting Blood Glucose
A fasting blood glucose test involves testing your blood after a period of at least eight hours without consuming any food or drink. A healthy fasting blood glucose result falls between 70 and 99mg/dL. If your fasting blood glucose falls between 100 and 125mg/dL, it indicates that your body's glucose control is impaired. Doctors generally classify this as pre-diabetes. A fasting blood glucose that exceeds 125mg/dL usually indicates that you are diabetic.
Oral Glucose Tolerance Test
An oral glucose tolerance test is used to check your blood glucose levels after consumption of a solution that contains 75g of glucose. This test measures your body's direct response to glucose. A healthy oral glucose tolerance result is less than 140mg/dL. If your oral glucose tolerance result falls between 140 and 200mg/dL, it indicates impaired glucose tolerance. Levels that exceed 200mg/dL usually indicate diabetes.
Considerations
Although most increases in blood sugar are caused by diabetes, other conditions may cause elevated blood glucose as well. Some possible causes include kidney failure, pancreatic cancer, inflammation of the pancreas, hyperthyroidism and certain medications. High blood sugar can also occur as a result of excessive food intake and acute stress, such as a trauma or a heart attack. While a blood glucose test can tell you if your blood sugar control is impaired, it does not single out an underlying cause. If your blood glucose tests are abnormal, further testing is necessary to determine the cause.
Hemoglobin A1c
If you are diabetic, another type of blood glucose test may be used to monitor your blood sugar levels and how well you are able to control them. This test, called a hemoglobin A1c or Hb A1c, measures your average blood sugar level over a period of three months. An ideal Hb A1c falls between 6 and 7 percent, although 7 to 8 percent still represents a low risk of complications. If your Hb A1c reaches 9 percent or more, you are at an increased risk for diabetic complications.
