Pericardial effusion is generally referred to as pericardial effusion and may be life-threatening if a large amount of pericardial effusion occurs in a short period of time. Pericardial effusion is the accumulation of fluid in the pericardial cavity due to infectious (e.g., tuberculous, septic) and noninfectious (e.g., rheumatic, uremic) causes. When a large amount of pericardial effusion occurs in a short period of time it can cause acute cardiac tamponade, which is manifested by sinus tachycardia, a drop in blood pressure, a decrease in pulse pressure, and a significant increase in venous pressure. If there is a significant decrease in cardiac output, acute circulatory failure and shock can result. However, if timely pericardiocentesis is performed to send the laboratory for pericardial effusion tests, to find Mycobacterium tuberculosis and cancer cells to confirm the nature of the effusion, and to decide on the next step in the treatment of pericardial effusion, it is usually not fatal. Therefore, when symptoms such as dyspnea and other suspected symptoms occur, you should consult a doctor in a timely manner to determine the cause of the disease and then give targeted treatment.