Acute pericarditis is not a common disease in daily life. What symptoms or clinical manifestations will appear after someone develops acute pericarditis? The clinical manifestations are mainly reflected in the following aspects: First, patients often experience chest pain and shortness of breath, and this pain often has a certain relationship with breathing. Second, the electrocardiogram often shows changes with ST segment elevation. Third, during a physical examination, doctors can often hear pericardial friction rub, or may feel the sensation of pericardial friction. Based on these symptoms and signs, doctors often make a diagnosis of acute pericarditis.