A 70-year-old female with type 2 diabetes and a blood glucose reading of "high" presents with confusion and dizziness. What is the most likely diagnosis?

The correct diagnosis in this scenario is hyperosmolar hyperglycemic nonketotic syndrome (HHNS). In older adults, particularly those with type 2 diabetes, HHNS can occur and is characterized by severely elevated blood glucose levels, often above 600 mg/dL, and the presence of hyperosmolarity in the blood. The condition also leads to confusion and dizziness, which aligns with the symptoms presented by the patient.

HHNS typically develops gradually and is often precipitated by factors such as infections, medications, or inadequate fluid intake, which can lead to dehydration. The severe hyperglycemia in this condition causes an increase in osmolarity, resulting in cellular dehydration and neurological symptoms, such as confusion.

Other potential diagnoses are less likely in this case. Diabetic ketoacidosis (DKA) is more common in type 1 diabetes and typically presents with ketosis, acidosis, and abdominal pain, which are not mentioned here. Acute renal failure can lead to hyperglycemia but would usually be accompanied by additional signs of kidney dysfunction. Hyperglycemia with moderate dehydration may describe the patient's condition but does not capture the severity and complexity present in HHNS, especially given the confusion and dizziness indicative of a more serious metabolic disturbance. Thus