Early symptoms of pericardial effusion are determined by the cause of the disease and the rate and amount of fluid produced. In the early stages when the pericardial effusion is small and the pressure in the pericardial cavity is not high, patients usually have no conscious symptoms. Some patients may experience a dull, distending pain with pressure in the chest. Pericardial effusion is caused by diseases of the pericardium itself, such as infectious pericarditis, or other causes involving the pericardium, such as puncture wounds, resulting in excessive fluid secretion in the pericardium and accumulation in the pericardial cavity. Early pericardial effusion is small, and the pressure in the pericardial cavity is not high, the patient usually has no conscious symptoms; some patients will have a dull pain of chest compression, distension and cardiac compression due to the continuous stretching of the pericardium, aggravated by coughing or deep breathing. Early symptoms of pericardial effusion are mild and can be treated with pericardiocentesis, anti-inflammatory therapy such as indomethacin, hormonal therapy such as prednisone, and surgical treatment such as pericardiocentesis and drainage when symptoms are more severe and drug therapy is ineffective. Pericardial effusion should be detected early, diagnosed early and treated early; if the patient is not feeling well, please consult the doctor immediately and follow the doctor’s instructions for standardized treatment.