What is a common cause of edema in the lower extremities?

Edema in the lower extremities often occurs due to heart failure because the condition leads to an impairment in the heart's ability to pump blood effectively. When the heart does not function optimally, it can cause blood to back up in the veins, particularly those in the legs and feet. This congestion results in increased hydrostatic pressure in the capillaries, leading to fluid leaking into the surrounding tissues and causing swelling, or edema.

In addition to heart failure, other factors such as kidney disease, liver disease, or even allergic responses can contribute to swelling, but the mechanism in heart failure is directly related to circulatory dynamics and is particularly common when considering edema due to systemic fluid overload associated with this condition.