Significance

• Glucose, like all blood tests, has an established range for normal values. Glucose levels above these values could be indicative of disease. Over a period of time, high glucose levels can cause damage to organs such as kidneys, eyes, heart and nerves.
  
  

Expected Glucose Results

• A normal fasting serum glucose level should fall between 70 and 110 mg/dL. Random--or non-fasting--values should rise slightly above the fasting level for a normal individual.
  
  

Diabetes Mellitus

• Diabetes mellitus is the primary cause of elevated serum glucose levels. The American Diabetes Association considers any fasting glucose level above 126 mg/dL, and any "casual" glucose level greater than or equal to 200 mg/dL "abnormally high" or "hyperglycemic."
  
  

Other Causes of Elevated Glucose Levels

• Other diseases and conditions that can cause elevated serum glucose levels include: stress related to severe trauma or heart attack; chronic renal failure; Cushing's syndrome; certain drugs such as diuretics, birth control pills, and lithium; overeating; and pancreatitis.
  
  

Further Testing

• An elevated glucose by itself does not automatically indicate diabetes. If your doctor suspects diabetes, she will order additional testing to confirm the diagnosis.