If a patient develops ankle sunken edema, the main causes to consider at this time include: First, for women of childbearing age, it is often considered that the edema may be idiopathic, that is, unexplained edema. After rest, the patient can often improve. Secondly, for example, in the case of long-term standing or remaining seated, the lower limbs are always in a sagging state, which can lead to sunken edema of the ankles. Thirdly, patients with kidney disease often have water and sodium retention due to a decrease in glomerular filtration rate, causing sunken edema of the ankle. Fourth, heart disease, due to various causes of cardiac insufficiency, may lead to reduced venous return due to reduced heart ejection fraction, resulting in sunken edema of the ankle. Fifthly, patients with liver disease or malnutrition may develop systemic hypoproteinemia, which may induce ankle sunken edema.