What is a common symptom of congestive heart failure?

Shortness of breath is a common symptom of congestive heart failure because the condition leads to fluid buildup in the lungs (pulmonary congestion) due to the heart's inability to pump blood effectively. When the heart fails to manage blood flow properly, it can cause the blood to back up into the pulmonary circulation, resulting in increased pressure in the lung capillaries. This pressure causes fluid to leak into the air sacs (alveoli) of the lungs, making it difficult for oxygen to be exchanged and leading to a feeling of breathlessness or dyspnea, especially during physical activity or when lying flat. This phenomenon, known as orthopnea, is a hallmark of congestive heart failure and is reflective of the compromised respiratory function associated with this condition.

Other symptoms like weight gain due to fluid retention, hypotension, or a rapid heartbeat can also occur in congestive heart failure, but the sensation of shortness of breath is particularly prominent and significant in the diagnosis and monitoring of this condition.