Foot swelling is a medical condition that is often caused by an abnormal growth of bone or tissue around the joint at the base of the big toe, known as a BUNION (6 letters). This can cause pain and inflammation in the foot, leading to swelling. In some cases, the swelling can be severe enough to limit mobility. Treatment for foot swelling due to a BUNION may include wearing wider shoes, using orthotics, or undergoing surgery.