What is the most common cause of pulmonary edema?

• A. Pneumonia
• B. Heart failure
• C. Acute respiratory distress syndrome
• D. Chronic obstructive pulmonary disease

Answer: (B)

The most common cause of pulmonary edema is heart failure. This condition occurs when the heart is unable to pump blood efficiently, leading to increased pressure in the blood vessels of the lungs. As a result, fluid seeps into the alveoli, the tiny air sacs in the lungs, causing pulmonary edema.

In heart failure, the heart muscle may be weakened or stiff, preventing it from receiving or pumping out blood effectively. This causes backup in the venous system and increased hydrostatic pressure, ultimately leading to fluid accumulation in the pulmonary interstitium and alveoli. The presence of excess fluid impairs gas exchange, leading to symptoms such as shortness of breath and decreased oxygen saturation.

While pneumonia, acute respiratory distress syndrome, and chronic obstructive pulmonary disease can also cause respiratory symptoms and complications, they are not the most common underlying causes of pulmonary edema. Pneumonia typically leads to fluid accumulation due to infection and inflammation in the lungs, while acute respiratory distress syndrome is characterized by widespread inflammation and can be caused by various factors, including trauma or sepsis. Chronic obstructive pulmonary disease may lead to respiratory distress and other complications but does not primarily cause pulmonary edema like heart failure does. Thus, heart failure stands out as the prevailing cause due to the mechanism