Pericardial friction can be detected by palpation on physical examination. Pericardial friction refers to the vibration generated by the friction of the dirty and wall layers of the pericardium when the heart beats, which is transmitted through the chest wall to the body surface and is felt as friction. When inflammatory changes occur in the pericardium, fibrin exudates and makes the surface rough, so it suggests that acute myocarditis causes fibrin exudation from the pericardium resulting in a rough surface. Examination requires exposure of the patient’s chest, placing the small piriformis muscle at the left edge of the sternum between the third and fourth intercostal space (the second auscultation area of the aortic valve), and then letting the patient perform inhalation, exhalation, inhalation, breath-holding, and exhalation, and there will be a sensation of paper friction in the asystolic phase, in the anteriorly tilted position, and even more pronounced at the end of the expiratory phase. If pericardial friction can be felt in the anterior region of the heart, timely medical treatment is needed to reduce the adverse effects of the disease through “early detection, early diagnosis, early treatment”.