The chest assessment is a cornerstone of the registered nurse's physical examination competency, requiring systematic evaluation of the respiratory, cardiovascular, and musculoskeletal structures contained within and surrounding the thoracic cage. A thorough understanding of thoracic anatomy, respiratory physiology, and the pathophysiological basis of abnormal findings is essential in nursing practice to detect, interpret, and communicate clinically significant changes that guide medical decision-making. The thoracic cage is formed by 12 pairs of ribs (7 true ribs articulating directly with the sternum via costal cartilages, 3 false ribs with cartilages joining the costal margin, and 2 floating ribs without anterior attachment), the sternum (manubrium, body, and xiphoid process), and the 12 thoracic vertebrae. The thorax contains the lungs (each divided into lobes: right upper, middle, and lower; left upper and lower), the heart within the mediastinum, the great vessels, the trachea, the mainstem bronchi, the esophagus, the thoracic duct, and the thoracic segments of the sympathetic trunk. Surface landmark identification is critical for accurate documentation and communication. The sternal angle (angle of Louis), the palpable ridge at the junction of the manubrium...