What causes swelling in the lower legs?

Common causes of leg edema include the following: 1. Heart disease: When the heart's ability to pump blood is weakened and it cannot effectively return blood to the heart, fluid may accumulate in dependent areas of the body, such as the legs. 2. Kidney disease: When the kidneys' ability to regulate fluid balance in the body is impaired, edema may occur. For example, nephritis or kidney failure. 3. Liver disease: Liver conditions such as cirrhosis can affect the production of proteins in the blood, which may lead to leakage of fluid from blood vessels and result in edema. 4. Medication side effects: Certain medications, such as diuretics, antihypertensive drugs, estrogen, or nonsteroidal anti-inflammatory drugs (NSAIDs), can also cause edema. 5. Pregnancy: Physiological edema commonly occurs in the later stages of pregnancy, primarily due to hormonal changes and increased blood volume. 6. Prolonged standing or sitting: Poor circulation can also lead to localized edema.