This case study examines a 20-year-old college student, Lara, who presented with symptoms of diabetes mellitus, including chronic hyperglycemia, dehydration, and hyperkalemia. The paper utilizes the clinical reasoning cycle to analyze Lara's condition. It involves the collection and interpretation of patient data, including physical examination findings and blood test results, to identify the core problem: undiagnosed diabetes. Goals are established to address immediate risks such as high blood glucose and hyperkalemia. The action plans include insulin administration, dietary adjustments, and intravenous fluids. The expected outcomes are evaluated through regular monitoring of blood glucose and potassium levels. The reflection highlights the importance of early detection and appropriate interventions for managing diabetes and its complications. The study emphasizes the need for continuous monitoring and patient education to prevent adverse outcomes such as dehydration and hyperkalemia, and the importance of immediate administration of insulin and saline.