Common causes of pericardial effusion include infectious factors, systemic diseases, tumor factors, drug factors, trauma and others. 1. Infectious factors: bacterial infections, such as tuberculosis, pneumococcus, etc.; viral infections, such as influenza virus; fungal infections, such as histoplasmosis, actinomycetes, etc.; and parasitic infections, such as amoebas, filarial worms, worms, etc., may cause pericardial effusion in patients. 2. Systemic diseases: including systemic lupus erythematosus, scleroderma, rheumatic fever, post-pericardiotomy syndrome, post-cardiac injury syndrome, acute myocardial infarction, pleurisy, intermural aneurysm, pulmonary embolism, and esophageal diseases, etc., which may cause pericardial effusion. 3. Tumor factors: lung cancer, bronchial cancer, breast cancer, interstitial skin cell tumor, sarcoma, etc., can also induce pericardial effusion. 4. Drug factors: pericardial effusion may also occur when patients take drugs such as procainamide, penicillin, isoniazid, and prednisone in the treatment of underlying diseases. 5. Trauma: non-penetrating chest trauma, post-thoracic surgery, cardiac catheterization or pacemaker implantation may cause pericardial effusion. 6. Other factors: acute non-specific pericarditis is also the cause of pericardial effusion. Patients with pericardial effusion may have other causes besides those described above, so they should consult a doctor in time to find out the cause of the disease and treat it actively to avoid delaying the disease.