Ankle swelling can be due to a number of issues, with cardiac issues likely to be the most concerning. Other causes include, but are not limited to, venous insufficiency (incompetent valves), venous thrombosis (clots in veins), kidney and protein disorders, and medications.

The heart is a pump and, if there is an issue, blood can back up. Given that we spend most of our time upright, gravity can pool this "backed up" fluid in the ankles and legs. The swelling or edema should be evaluated by your physician and tests may need to be performed to see if heart issues are involved in the swelling. The amount of swelling is important and, if severe, should be evaluated aggressively.