The 57-year-old female presented with consciousness disturbance and fever for one day. Her physical examination revealed an altered mental status and hyperglycemia. Laboratory tests showed severe hyperglycemia, hyperosmolality, and acute kidney injury. She was diagnosed with type 2 diabetes mellitus with hyperglycemic hyperosmolar state and urinary tract infection. She received aggressive hydration, insulin infusion, electrolyte monitoring, antibiotic treatment, and blood and urine cultures. Her mental status and laboratory abnormalities improved with treatment.