What is the normal fasting blood sugar level?

A normal blood sugar level after fasting for eight hours is 70 to 100 mg/dL, according to MedlinePlus. A fasting blood sugar test is common in screening for diabetes.

Blood sugar levels of 100 to 125 mg/dL indicate impaired fasting glucose, a type of prediabetes that increases the risk of developing Type 2 diabetes. A level of 126 mg/dL or higher indicates diabetes. Higher-than-normal levels can also result from other medical conditions, including an overactive thyroid gland, pancreatic cancer, inflammation of the pancreas, stress due to trauma, and rare tumors. An abnormal test result for someone with known diabetes may mean the condition is not properly controlled.