Swelling from the ankles, feet, or legs is usually due to fluid buildup, also called oedema. This happens when extra fluid leaks from blood vessels and accumulates in the encompassing tissues. Some typical causes of swollen ankles and feet involve: Does taking in a lot of salt trigger leg swelling? https://www.sgvascularctr.com/swollen-leg-why-do-i-have-it-and-what-can-i-do/