Generally speaking, the pericardium has four functions: fixation and barrier protection, preventing over-distension of the heart, stopping the spread of infection, and cushioning. 1. Fixation and barrier protection: The pericardium is a double-layered bag structure outside the heart, located in the middle mediastinum, which serves as a fixation and barrier protection for the heart, and can protect the heart from external pressure. 2. Prevents over-expansion of the heart: When normal, the pericardium prevents over-expansion of the heart and maintains a constant blood volume to minimize the risk of over-impairment of the heart’s function. 3. Prevents the spread of infection: The pericardium is a natural barrier. For example, if there is an infection in the lungs or chest cavity, the pericardium can block the invasion of some of the pathogenic bacteria, thus reducing the risk of heart infection. 4. Cushioning: The pericardium and the plasma in the pericardial cavity can also slow down the impact of cardiac contractions on the surrounding blood vessels. If there is any cardiac discomfort, it is recommended to go to the hospital for timely examination.