Differential Diagnosis for Acute Hyperglycemia in an 80-year-old Male with No History of Diabetes

Single Most Likely Diagnosis

• Stress-induced hyperglycemia: This is the most likely diagnosis due to the body's stress response, which can cause hyperglycemia in the absence of diabetes, especially in elderly patients who may have underlying health conditions or be experiencing acute illness or injury.

Other Likely Diagnoses

• New-onset diabetes mellitus: Although the patient has no history of diabetes, it's possible that he has undiagnosed diabetes that is being unmasked by an acute illness or other stressor.
• Medication-induced hyperglycemia: Certain medications, such as steroids, certain antibiotics, and some psychiatric medications, can cause hyperglycemia as a side effect.
• Pancreatic disorders: Conditions like pancreatitis or pancreatic cancer can cause hyperglycemia due to damage to the pancreas.

Do Not Miss Diagnoses

• Septicemia or severe infection: Hyperglycemia can be a sign of severe infection, which can be life-threatening if not promptly treated.
• Myocardial infarction: Hyperglycemia can occur in the setting of a heart attack, even in patients without a history of diabetes.
• Stroke: Hyperglycemia can also be a sign of stroke, which requires immediate medical attention.

Rare Diagnoses

• Endocrine disorders: Conditions like Cushing's syndrome, pheochromocytoma, or glucagonoma can cause hyperglycemia, although these are relatively rare.
• Genetic disorders: Certain genetic disorders, such as hemochromatosis, can increase the risk of developing diabetes and hyperglycemia.
• Other rare pancreatic disorders: Conditions like pancreatic neuroendocrine tumors or cystic fibrosis can also cause hyperglycemia, although these are less common.