What is a key feature of congestive heart failure (CHF)?

Congestive heart failure (CHF) is primarily characterized by the heart's inability to pump blood effectively. In CHF, the heart muscle becomes weak or stiff, leading to a reduced capacity to maintain adequate blood circulation to meet the body's needs. This results in a variety of symptoms, including fatigue, shortness of breath, and fluid retention.

As the heart struggles to function properly, it can lead to congestion in the lungs and other parts of the body, which is where the term "congestive" comes from. The impaired pumping action causes blood to back up in the veins, leading to increased pressure in the pulmonary circulation and often resulting in pulmonary congestion.

This key feature is distinct from the other choices provided. Increased production of urine can occur in certain situations related to body fluid status but is not a defining characteristic of CHF, as the condition often leads to fluid retention rather than increased urination. Air in the pleural space, known as pneumothorax, is a separate condition that does not relate directly to the heart's function. Lastly, while severe chest infections can occur in patients with CHF due to fluid accumulation in the lungs, they are not a core feature of the condition itself. Thus, the inability to pump blood effectively is the