The presence of edema in one ankle and not in the other foot indicates that the edema is a localized lesion. How to treat and what medications to take need to be determined on a case-by-case basis. If the ankle edema is caused by inflammation, you need to apply the appropriate local anti-inflammatory drugs. If it is caused by gouty nodules, you need to apply painkillers and drugs to reduce uric acid in order to achieve the purpose of reducing swelling, and in severe cases, you can eat part of the glucocorticoid. If it is caused by trauma, you can only rest or go to the surgery for appropriate treatment. If the edema is caused by unilateral lower extremity vascular reflux or thrombus, it is necessary to do lower extremity vascular ultrasound or take anti-thrombotic drugs to achieve the purpose of reducing swelling. So one side of the foot edema, but not the other side of the edema, often local causes, according to the actual situation to use different treatment measures, using different drugs to achieve the purpose of treatment.