Post-operative assessment is a systematic evaluation of the patient's physiological status following surgical procedures, guided by knowledge of the specific surgical intervention, anesthetic agents used, and anticipated complications. The initial assessment follows the ABCs: Airway patency (risk of laryngospasm, residual neuromuscular blockade, tongue obstruction), Breathing adequacy (hypoventilation from residual anesthesia, atelectasis from shallow breathing, pneumothorax from thoracic procedures), and Circulatory stability (hemorrhage from surgical site, hypovolemia, third-spacing, cardiac arrhythmias). Pain assessment and management are critical in the immediate post-operative period, as uncontrolled pain increases sympathetic activation (tachycardia, hypertension, vasoconstriction), impairs respiratory effort (splinting causes atelectasis and pneumonia), and delays mobilization (increasing DVT risk). Post-operative complications follow predictable timelines: hemorrhage and airway compromise within hours, atelectasis and ileus within 24-48 hours, surgical site infection at days 3-5, DVT at days 5-7, and pulmonary embolism at days 7-10. The nurse performs serial assessments of vital signs, pain, surgical site (drainage amount and character, wound approximation), neurovascular status of affected extremities, urinary output, bowel function, and mental status, manages the transition from parenteral to oral analgesics, implements VTE prophylaxis, and promotes early mobilization.