The main causes of acute pericarditis are many, such as infectious factors, metabolic factors, radioactive factors, traumatic factors, drug factors, tumor factors, etc., which need to be analyzed specifically. However, regardless of which factors are caused, it is recommended to go to the regular hospital as soon as possible to receive treatment.1, infectious factors: common pathogens are streptococcus, pneumococcus, staphylococcus, viruses, fungi, parasites and so on. There are also more routes of infection, for example, in cases of pneumonia and pyothorax, one is that bacteria enter the pericardial cavity directly from the lungs and pleura or through the lymphatic route, and the other is that bacteria enter the pericardial cavity through the subdiaphragm or liver abscess by directly penetrating the diaphragm, etc.; 2. Metabolic factors: mainly caused by diseases of other organs or tissue systems, for example, rheumatic fever, systemic lupus erythematosus, hypothyroidism, AIDS, etc.; 3. Radiological factors: Generally seen after radiotherapy, related to inflammation caused by radiation stimulation; 4, traumatic factors: for example, cardiac contusion or catheter penetration injuries, pericardial blood accumulation, stimulation of the pericardium to cause inflammatory reaction, acute pericarditis; 5, drug factors: common drugs include hydralazine, procainamide, phenytoin sodium, isoniazid, methicarbazone, etc., mainly due to the cardiotoxicity produced by the drug, stimulation of the pericardium caused by Tumor factors: common tumors include lung cancer, esophageal cancer, breast cancer, lymphoma and so on. It is mainly due to the infiltration or metastasis of cancer to the pericardium causing acute pericarditis.