Foot swelling, medically known as edema, occurs when excess fluid becomes trapped in the tissues of the lower limbs. Mild swelling may simply make shoes feel tight after a long day of standing, sitting, or exposure to heat. Temporary causes can include minor injuries or restrictive footwear. However, swelling that appears suddenly, worsens progressively, affects only one foot, or is accompanied by pain, redness, or breathing difficulty should not be ignored. These signs may indicate underlying circulatory, cardiac, renal, or hepatic concerns that require medical evaluation.
Poor circulation is one frequent cause. When blood flow slows due to prolonged sitting, smoking, or vascular conditions, fluid can pool in the legs and feet. Elevating the legs or increasing movement may ease mild cases. More serious causes include heart-related conditions such as congestive heart failure, where the heart struggles to pump blood effectively, leading to fluid buildup in both feet and ankles. Warning symptoms may include fatigue and shortness of breath.