Pericardial effusion may not cause any noticeable signs and symptoms, particularly if the fluid has increased slowly. If pericardial effusion signs and symptoms do occur, they might include: 
Shortness of breath or difficulty breathing (dyspnea)
Discomfort when breathing while lying down
Chest pain, usually behind the breastbone or on the left side of the chest
Chest fullness
Lightheadedness or feeling faint
Swelling in the abdomen or legs
