What is a significant indicator of severe heart failure?

Fatigue on exertion is a significant indicator of severe heart failure because it reflects the heart's diminished ability to pump blood effectively. In heart failure, the heart struggles to provide enough oxygen-rich blood to meet the body's demands, especially during physical activity. As a result, individuals often experience increased fatigue and weakness even with minimal exertion, which can severely impact daily activities and overall quality of life.

In the context of heart failure, other symptoms may also present, such as shortness of breath, fluid retention, and reduced exercise tolerance, making fatigue a critical sign of severe disease progression. Monitoring such symptoms helps healthcare providers assess the severity of heart failure and adjust treatment plans accordingly.