Pulmonary edema is a condition where excess fluid builds up in the lungs, causing shortness of breath. It can be caused by heart problems, pneumonia, high altitudes, toxins, chest trauma, and other issues. Symptoms include difficulty breathing, coughing, chest pain, and fatigue. Treatment focuses on oxygen therapy, medications to reduce fluid buildup and control blood pressure, and managing any underlying conditions that may be causing the pulmonary edema.