Arterial blood gas (ABG) analysis is a critical diagnostic tool used to assess a patient's oxygenation, ventilation, and acid-base status by measuring parameters such as pH, partial pressures of oxygen (PaO2) and carbon dioxide (PaCO2), bicarbonate (HCO3-), and oxygen saturation. It is essential for managing patients with respiratory, metabolic, and critical illnesses, providing insights into the underlying physiological and pathophysiological processes.