Which of the following can be a sign of congestive heart failure?

Swelling in the legs and ankles is a classic sign of congestive heart failure (CHF). In this condition, the heart's ability to pump blood effectively is compromised, leading to fluid retention in various parts of the body, particularly in the lower extremities. This occurs due to increased pressure in the blood vessels, causing fluid to leak into surrounding tissues. The swelling, known as peripheral edema, is a direct result of this fluid accumulation and is often one of the first signs observed in patients with CHF.

The other options do not typically characterize congestive heart failure. Increased appetite might be seen in certain conditions but is not associated with CHF, while rapid weight loss could indicate dehydration or other serious issues unrelated to heart failure. Fever, on the other hand, suggests an infection or inflammatory process rather than a failure of cardiac function. Thus, the presence of swelling in the legs and ankles serves as a clear indicator of congestive heart failure.