Swollen legs and ankles are often blamed on standing or sitting too long, but persistent swelling can signal something more. Known as edema, it happens when excess fluid builds up in the body’s tissues. Temporary puffiness may ease with rest, but swelling that keeps coming back, appears without a clear reason, or comes with other symptoms should not be ignored. Knowing the difference helps protect your overall health.

Poor circulation is a common cause of ongoing leg swelling. When blood doesn’t return to the heart efficiently, fluid pools in the lower legs, leading to heaviness and discomfort. Long periods of sitting or standing, aging, and vein disorders all play a role. Too much sodium can worsen fluid retention, while varicose veins occur when weak valves let blood collect in the legs. For mild cases, cutting back on salt, staying active, and drinking water can help.

Swelling can also be linked to the heart, kidneys, or liver. Heart failure can reduce circulation, and kidney or liver problems can disrupt fluid balance, causing swelling in the legs, abdomen, or around the eyes. These issues often come with fatigue, shortness of breath, chest discomfort, or weight gain, and they require medical evaluation.

Sudden swelling in one leg with pain, warmth, or redness may be deep vein thrombosis, a blood clot that needs urgent care. See a provider promptly if swelling affects only one leg, doesn’t improve with rest, keeps returning, or occurs with chest pain or breathing trouble.