Pressure (symbol: p or P) is the force applied perpendicular to the surface of an object per unit area over which that force is distributed. Gauge pressure (also spelled gage pressure) is the pressure relative to the ambient pressure.
Cardiogenic pulmonary edema. Pulmonary edema that is due to a direct problem with the heart is called cardiogenic. Congestive heart failure is a common cause of cardiogenic pulmonary edema; in this condition, the left ventricle cannot pump out enough blood to meet the needs of the body. This causes a buildup of pressure in other parts of the circulatory system, forcing fluid into the air sacs of the lungs and other parts of the body.
Pulmonary Edema. Pulmonary edema occurs when fluid accumulates in the alveoli in the lungs. This type of edema is usually caused by a blockage in the veins, with fluid filling the lungs as blood pressure rises. When the pleural cavity also fills with fluid, it's a form of pulmonary edema called pleural effusion.