Hyperglycemia

An abnormally elevated blood glucose concentration above the reference range (fasting glucose >5.5 mmol/L [>99 mg/dL] or random blood glucose >7.8 mmol/L [>140 mg/dL]), typically reflecting impaired insulin secretion, insulin resistance, or increased hepatic glucose production.

Causes

• Diabetes mellitus

  • Missed insulin or glucose-lowering medication

  • Inadequate insulin dosing

  • Insulin resistance

• Dietary and lifestyle causes

  • High intake of sugary (carbohydrates) foods or beverages

  • Physical inactivity

• Physiological causes

  • Stress with increased cortisol and catecholamine release

  • Dawn phenomenon

• Infectious and systemic causes

  • Acute illness

  • Infection

  • Sepsis

  • Trauma or surgery

• Medication-related causes

  • Corticosteroids

  • Thiazide diuretics

  • Atypical antipsychotics

• Endocrine causes

  • Cushing syndrome

  • Acromegaly

  • Hyperthyroidism

  • Pheochromocytoma

  • Glucagonoma

  • Gestational diabetes

• Total parenteral nutrition