This assignment analyzes a case study of Mr. Smith, an elderly patient experiencing fluid and electrolyte imbalances. The analysis covers the physiological changes associated with aging, including renal senescence and hormonal control defects, leading to conditions such as hypernatremia and hyponatremia. It explores the impact of vomiting, diarrhea, and medications like Furosemide and Lisinopril on electrolyte levels and discusses the implications of renal failure. The assignment includes a discussion of diagnostic findings, such as inelastic skin, oliguria, and specific treatments, including intravenous potassium administration. The solution also provides rationales for the choices made, referencing key concepts like loop diuretics and ACE inhibitors, and concludes with relevant references.