What Is Abnormal Glucose?

According to the National Institutes of Health, glucose is a sugar in blood that the body converts to energy 3. The energy produced from the metabolizing of glucose allows for proper cellular functioning. When glucose levels are abnormal, the amount of sugar in the blood is either too high or too low for proper physical functioning.


The Mayo Clinic notes that maintaining normal glucose levels is significant to overall health and physical functioning. Abnormal glucose levels can place stress on the body and lead to long term health complications. It is critical for people to monitor their glucose levels if they've been diagnosed with a health issue related to glucose levels, such as hypoglycemia or diabetes.

Types of Tests

The American Association for Clinical Chemistry notes that there are a variety of tests used to assess glucose levels 1. A fasting blood glucose test is typically completed between 8 to 10 hours after the last meal. An oral glucose tolerance test may be completed if a patient has elevated glucose levels and his doctor wants to rule out the presence of diabetes. A gestational diabetes test is completed during pregnancy to check for possible onset of gestational diabetes, a condition that causes abnormally high glucose levels during the later phase of pregnancy.

Test Results

The American Association for Clinical Chemistry notes that a normal fasting glucose test result is in the range of 70 to 99 mg/dL 1. Abnormally high results are at 100 mg/dL, or above, with levels above 126 mg/dL indicating diabetes. Normal values for glucose tolerance tests are less than 140 mg/dL. Results that fall above or below the specified ranges are consider abnormal.


The Mayo Clinic notes that prevention of abnormal glucose levels typically requires a balanced diet and food portion control. Overeating or consuming excess carbohydrates or sugars can result in abnormal glucose levels. In addition to a having a healthy diet, individuals with diabetes may have to use medications or insulin to regulate their glucose levels.

Expert Insight

The American Association for Clinical Chemistry suggests that blood glucose tests may be used to test healthy people for diabetes 1. Since diabetes can occur with very few symptoms, and it is a common disease, many medical professionals may screen for it during routine physical exams. The National Institutes of Health also note that abnormal glucose levels can be the result of conditions such as hypothyroidism, and a medical professional may order additional laboratory tests to rule out any possible conditions related to abnormal glucose levels 3.