Swollen legs, also known as leg oedema, can be caused my multiple factors. These can include: - Fluid Retention This is one of the most common causes of swollen legs. It can result from factors such as prolonged sitting or standing, high salt intake, certain medications, or an underlying medical condition. Injury or Trauma Injuries to the legs, such as sprains, strains, or fractures, can lead to swelling as the body's natural response to inflammation. Infection Infections,