If a person’s legs appear sunken when pressed, it means that puffiness may be present. Of course what the swelling is due to needs to be judged on the basis of the actual situation. If the phenomenon occurs in one leg, it is possible that the swelling in one leg is caused by trauma, inflammation, or unilateral limb thrombosis. Patients need to do the appropriate tests, as well as vascular ultrasound, for differential diagnosis. If swelling is present in both feet, or both legs, it is caused by systemic disease. Of course, before diagnosing systemic disease, it is necessary to exclude local lesions, such as swelling caused by bilateral lower extremity atherosclerosis. The most common systemic pathologies are heart disease and kidney disease, and of course endocrine system disease and rheumatic system disease. Heart disease and kidney disease are more common. Heart disease with bilateral lower extremity edema often indicates symptoms of heart failure, with inability to lie down at night or palpitations after activity. Kidney disease with bilateral foot edema or bilateral lower extremity edema indicates more serious kidney disease, and foam in the urine may be more increased, requiring further examination for active treatment.