Cardiac tamponade is a medical emergency that occurs when blood or other fluids accumulate in the pericardium, the sac around the heart, leading to compression of the heart. This condition is also known as pericardial tamponade, pericardial effusion, or simply tamponade. In addition, some physicians may refer to it as hemopericardium if the accumulation is blood specifically. Symptoms can be severe and life-threatening, including shortness of breath, chest pain, and low blood pressure. Treatment usually involves draining the fluid from the pericardium, and in severe cases, surgery may be necessary to relieve pressure on the heart. Early recognition and intervention can greatly improve outcomes for patients with cardiac tamponade.