When the feet feel swollen, it is important to determine whether it is really swollen. You can press the back of the patient’s foot and ankle to see whether there will be indentation and whether the indentation can recover quickly, so as to determine whether there is edema. Usually, foot swelling may be caused by the following factors: i. Local factors: 1. Reflux disorder: If the patient has bilateral edema asymmetry, it is usually seen as reflux disorder, most commonly venous reflux disorder. At this time, patients can do lower limb vascular ultrasound to determine the presence of thrombosis, varicose veins and other factors affecting lower limb reflux; 2. Local diseases: If the swelling is locally red, swollen and painful, there is a possibility of gouty arthritis. In addition, the presence of dermatophytosis can be judged according to local color and temperature. 2. Systemic factors: If bilateral edema is symmetrical, systemic causes need to be considered, usually seen in cardiogenic edema, hepatogenic edema, endocrine-derived edema, nephrogenic edema, and unexplained edema, etc., all of which may cause the feet to feel swollen.