One of the signs of left-sided heart failure is:

In the context of left-sided heart failure, pulmonary edema is a key sign. This condition occurs because the left side of the heart is responsible for pumping oxygenated blood from the lungs to the rest of the body. When the left ventricle fails to effectively pump blood, pressure builds up in the pulmonary veins, leading to fluid leakage into the lung tissues and alveoli. As a result, patients experience symptoms such as shortness of breath, which can be particularly pronounced when lying down, causing orthopnea or paroxysmal nocturnal dyspnea.

This condition is distinct from other signs like peripheral edema and jugular venous distention, which are more commonly associated with right-sided heart failure, where blood backs up into the systemic circulation, resulting in fluid accumulation in the extremities and increased pressures in the venous system. Understanding these nuances is essential for recognizing the specific manifestations of heart failure and guiding appropriate management.