High Fasting Blood Sugars: Hyperglycemia and Managing Blood Sugar Levels

Hyperglycemia: Blood Sugar Levels

The phrases “fasting blood sugar”, “fasting glucose levels” and “fasting blood glucose” are used interchangeably and frequently in the diabetes community. Such blood sugar levels are determined after an individual has fasted for a period of eight hours. These fasting numbers are indicative of how much glucose (or sugar) is in one’s bloodstream. Individuals with prediabetes will typically be diagnosed as having type 2 diabetes if their blood sugars cannot be controlled.


Too much glucose suggests hyperglycemia, a condition that, if left untreated, can lead to diabetes complications, such as diabetic coma, retinopathy and diabetic ketoacidosis. In general, glucose levels that trigger fasting hyperglycemia are blood sugar levels over 90-130 mg/dL.[1] However, some health care providers may diagnose patients with mild fasting hyperglycemia with fasting blood sugars greater than 109 mg/dL in adolescents and adults, and 100 mg/dL in prepubescent children, according to emedicinehealth.[2]

High Fasting Blood Sugars: Hyperglycemia Causes

Blood glucose levels high in nature are the result of an overabundance of sugar in the bloodstream. Diabetes medications, such as metformin or insulin, aid in lowering blood sugar. Without the aid of medicinal therapy, high blood sugar will typically result.

Factors contributing to high fasting blood sugars include:

  • Stress
  • Sickness
  • Physically inactive or, by contrast, strenuous activity
  • Overconsumption of food and calories
  • Inadequate insulin or diabetes medication dosage
  • Skipping diabetic medication
  • Not following a personalized diabetic diet
  • Taking certain medications from the following classes are known to raise blood sugar levels:
    • Oral contraceptives
    • Atypical antipsychotics
    • Corticosteroids
    • Diuretics
    • Phenothiazines
    • Beta blockers
    • Specific medications: Dextrose, diazoxide, furosemide, glucagon, epinephrine, lithium, isoniazid, nicotinic acid, triamterene and phenytoin.[3]

Hyperglycemia: Treatment Options

Several high fasting blood sugars may warrant a physician advised treatment plan that includes drinking plenty of water to flush excess glucose out of his or her system, increasing physical activity, implementing a diabetic meal plan and making necessary medication adjustments for adequate glucose control.

Prevention Tips: How to Lower Blood Sugar

Physicians will assign blood sugar target ranges for their patients that are specific to their personal health situation. As a result, blood sugar levels are better maintained, thus, preventing hyperglycemia. To keep their glucose levels in check, diabetics should monitor their daily blood sugars through at-home blood sugar testing and quarterly in-office hemoglobin A1C (HbA1C) testing. In doing so, they will gain an accurate perspective on their diabetes management.

Other preventative measures include incorporating frequent exercise into their routine and following a personalized diabetic diet that distributes carbohydrates throughout the day.

Disclaimer: The preceding information should not replace medical advice by a licensed physician.


MedicineNet. “Hyperglycemia and Diabetes”, https://www.medicinenet.com/hyperglycemia/article.htm.[1]

Emedicinehealth. “High Blood Sugar (Hyperglycemia)”, https://www.emedicinehealth.com/high_blood_sugar_hyperglycemia/article_em.htm.[2]

South Dakota Diabetes Prevention and Control Program. Recommendations for Management of Diabetes in South Dakota, 2008.[3]

Mayo Clinic. “Hyperglycemia in Diabetes”, https://www.mayoclinic.com/health/hyperglycemia/DS01168/METHOD=print.

Patient Resources

Joslin Diabetes Center, https://www.joslin.org/.

American Diabetes Association, https://www.diabetes.org/.

Diabetes Forecast Magazine, https://forecast.diabetes.org/.