Pericardial effusion may present dangerous conditions such as dyspnea, dysphagia, decreased blood pressure, shock, etc. Pleural effusion may present symptoms such as dyspnea, and may also compress the heart and lungs, which may be life-threatening in severe cases. 1. Pericardial effusion: Pericardial effusion, if the amount is large, will compress the bronchial tubes or lungs, which will lead to pulmonary stasis, and the patient will suffer from respiratory difficulties, hypoxia, and other risks; a large amount of pericardial effusion will compress the heart, which will lead to a decrease in cardiac output, a decrease in blood pressure, and even shock. 2. Pleural effusion: pleural effusion will compress the lungs, affecting the respiratory system, patients will experience dyspnea and hypoxia, pleural effusion compressing the heart may cause myocardial ischemia, angina, hypoxia and ischemia may be life-threatening in severe cases. The presence of pericardial effusion or pleural effusion should be timely medical treatment, so as not to delay the condition.