In case of swollen feet in summer, it is important to pay attention to whether the patient has swollen feet on one side or on both sides. If the foot swelling is bilateral, we need to see whether the patient has other corresponding clinical symptoms, such as whether there is abdominal distension, shortness of breath after activity, and whether the face is swollen in the morning. If the edema is unilateral, it is caused by poor venous return or poor lymphatic return. Bilateral edema of the feet should be considered for cardiac insufficiency, renal insufficiency or liver disease. In addition, drugs, rheumatic immune system diseases, and hormone secretion may cause bilateral foot swelling in the lower extremities. Therefore, a comprehensive analysis must be made clinically based on the patient’s condition, underlying diseases, other symptoms and various factors such as unilateral foot swelling and bilateral foot swelling before a clear diagnosis can be given.