Lung ultrasound has emerged as a powerful bedside tool for evaluating pulmonary pathology. Normal aerated lung produces a characteristic sliding sign (pleural movement with respiration) and A-lines (horizontal reverberation artifacts). Loss of lung sliding suggests pneumothorax; B-lines (vertical artifacts extending to the bottom of the screen that move with breathing) indicate interstitial edema or consolidation. Pleural effusions appear as anechoic collections above the diaphragm. Lung ultrasound has high sensitivity for many acute pulmonary conditions and is increasingly used in emergency and critical care settings.