Which of the following is a major sign of heart failure?

Exertional dyspnea is a major sign of heart failure and refers to shortness of breath that occurs during physical activity. This symptom arises because the heart’s impaired ability to pump blood effectively leads to fluid accumulation and poor oxygenation of the body's tissues, particularly during exertion. In individuals with heart failure, the heart struggles to meet the increased demands of the body when active, resulting in difficulty breathing. This manifestation is critical for diagnosing and managing heart failure, as it affects a patient's functional capacity and quality of life.

While hypertension, weight gain, and joint pain can be associated with heart failure, they do not directly indicate the heart's failure to pump efficiently in the same way that exertional dyspnea does. Hypertension is a risk factor for developing heart failure rather than a direct sign, weight gain can occur from fluid retention but is not exclusive to heart failure, and joint pain typically relates to musculoskeletal issues rather than cardiac problems.