If a patient has a swollen foot, the causes include foot trauma, gout, poor blood circulation, etc., as follows: a. Foot trauma: After trauma, it will easily lead to swelling, pain and limited movement of one foot. Second, gout: gout in the foot will also lead to a foot swelling. Poor blood circulation: poor blood circulation in one lower extremity, such as varicose veins, venous valve closure, venous thrombosis, etc., will also lead to swelling in one foot. Therefore, after a patient has swelling in one foot, he or she must consult a doctor to see what causes it and treat the cause to promote the reduction and recovery of swelling. When one foot is swollen, it is important to avoid standing for a long time, squatting, running and jumping to avoid aggravating the swelling. When swelling is obvious, the affected limb can be elevated and blood-stasis-boosting drugs can be applied to promote the absorption and reduction of swelling.