Pericardial effusion is a medical condition characterized by the accumulation of fluid in the pericardial sac surrounding the heart. This fluid buildup can put pressure on the heart and restrict its ability to pump blood efficiently. Pericardial effusion can be caused by a variety of factors, including infections, inflammation, trauma, cancer, or certain medical treatments. Symptoms of pericardial effusion can vary depending on the amount of fluid present and may include chest pain, shortness of breath, palpitations, or fatigue. Treatment for pericardial effusion may involve draining the fluid through a procedure called pericardiocentesis, medication, or surgery. Without proper treatment, pericardial effusion can lead to serious complications, such as cardiac tamponade, which is a life-threatening condition that requires immediate medical attention.