The tests usually required for a small amount of pericardial effusion include physical examination, chest X-ray, electrocardiogram, echocardiogram, and pericardiocentesis. 1. Physical examination: Check for signs of hypotension, elevated jugular venous pulsation, increased pulse pressure, and decreased systolic blood pressure after inspiration. The stethoscope may also be used to check for muffled heart sounds and pericardial friction. 2. Chest X-ray: An X-ray may show an enlarged heart, which may assist in the diagnosis of pericardial effusion. 3. Electrocardiogram: Low voltage is often present, tachycardia is present, and alternating voltage is seen in cases of massive effusion. 4. Echocardiography: Fluid dark areas are seen between the anterior walls of the heart and behind the posterior walls of the heart. 5. Pericardiocentesis: It can confirm the existence of pericardial effusion, relieve the symptoms of pericardial tamponade, and retain part of the effusion for laboratory tests related to the etiology. Pericardial effusion needs to be examined and diagnosed under the guidance of a doctor and treated actively to avoid aggravation of a small amount of pericardial effusion and the appearance of obvious symptoms, which will affect the health of the body.