Which of the following is a common symptom of heart failure?

Shortness of breath is a hallmark symptom of heart failure and occurs due to the heart's reduced ability to pump blood effectively. When the heart struggles to circulate blood efficiently, fluid can accumulate in the lungs, leading to pulmonary congestion which results in difficulty breathing, especially during exertion or when lying flat. This phenomenon reflects the underlying pathophysiology of heart failure, where fluid overload and decreased cardiac output lead to increased pressure in the pulmonary circulation and resultant pulmonary edema.

Dizziness, weight loss, and increased appetite may occur in patients with various medical conditions, including those associated with heart failure, but they are not the primary or most common symptoms. Dizziness can stem from poor perfusion or low blood pressure, weight loss could happen over time in chronic heart failure due to factors such as anorexia or metabolic changes, and increased appetite is generally not associated with heart failure, where patients often experience a diminished appetite due to various factors including fullness from fluid retention.