If patients with COPD have swollen feet, they are generally considered to have pulmonary heart disease and heart failure, and further examination of chest CT, electrocardiogram, cardiac color ultrasound, as well as lower extremity vascular ultrasound is needed to assess the extent of pulmonary heart disease and heart failure. If the foot is swollen unilaterally, it is necessary to be alert to the deep vein thrombosis of the lower limbs caused by chronic obstructive pulmonary disease patients who have been bedridden for a long time. If patients with chronic obstructive pulmonary disease, pulmonary heart disease and heart failure are on oxygen, bedridden for a long period of time, or even non-invasive ventilator-assisted therapy, and the patients are malnourished, it is also necessary to suspect that the swelling of the feet is related to hypo-proteinemia, which means that there is a relationship with malnutrition. Therefore, the relationship between swollen feet and lungs mainly depends on the presence of chronic lung disease, dietary status, and the usual treatment status. If the patient with swollen feet also has hypertension, diabetes mellitus, coronary artery disease, etc., the relationship with the lungs can also interact with each other, and chest imaging, electrocardiogram, cardiac ultrasound, liver and kidney function, and thrombus indexes need to be improved to further evaluate the patient’s specific situation.