Pericardial fluid is a clear, straw-colored liquid found in the pericardial sac, which surrounds the heart. This fluid acts as a lubricant, reducing friction between the heart and the surrounding tissues as the heart beats. It also helps to cushion the heart, providing a protective layer against physical shocks. The amount of pericardial fluid is usually small, but it can increase due to conditions like pericarditis or pericardial effusion. Excess fluid can lead to complications, such as pressure on the heart, which may affect its ability to pump blood effectively. Regular monitoring is important for maintaining heart health.