What can cause orthopnea?

Orthopnea refers to the difficulty in breathing that occurs when a person is lying flat and is relieved by sitting up or standing. The underlying cause of orthopnea is often related to conditions that affect the heart and lungs.

Left ventricular heart failure is specifically known to cause orthopnea because when the left ventricle fails to pump blood effectively, blood can back up into the pulmonary circulation, leading to pulmonary congestion. When a person lies flat, the increased venous return to the heart exacerbates this congestion, making it more difficult for them to breathe. As they sit up or elevate their upper body, this pooled blood is redistributed, providing relief and improving breathing.

While conditions like pneumonia, right ventricular failure, and gastroesophageal reflux can cause breathing difficulties, they do not typically result in orthopnea as a primary symptom. For instance, pneumonia may cause dyspnea but is more associated with symptoms that don't follow the positional pattern seen in orthopnea. Right ventricular failure primarily leads to systemic congestion rather than pulmonary congestion, and gastroesophageal reflux can lead to symptoms such as heartburn or cough, but not typically orthopnea. These distinctions clarify why left ventricular heart failure is the most appropriate choice in this context.