Swelling and pain at the edge of the toe bunion may be caused by bunionitis, bunion trauma, bunion and other diseases. 1. Bunion: Inflammation of the nail groove and its surrounding tissues along both sides of the bunion, often caused by small traumas of the skin around the nail, such as tearing barbs, nail biting, excessive manicure, ingrown nails and so on, resulting in the destruction of the normal skin barrier, followed by bacterial, fungal and other pathogenic microorganisms infections, manifested as redness, swelling, heat, pain, and in severe cases, there can be abscesses formed in the peri-ungual tissues. 2. Bunion trauma: Extrusion, violent blows, impact, crushing, improper force, etc. can lead to lesser toe trauma, local tissue congestion, edema, or even bleeding, causing pain and swelling at the outer edge of the bunion. Patients often have a clear history of trauma. 3. Bunion: The first metatarsal bone returns to the inside, and the bunion is inclined to the outside. It is associated with prolonged standing, excessive walking, frequent wearing of high-heeled and pointed shoes, heredity and other factors. It is often characterized by symmetrical bunion pain and deformity, which may be accompanied by pain in wearing shoes and difficulty in walking. Swelling and pain on the edge of the toe bunion may also be caused by gouty arthritis, bunion tumor and other diseases, it is recommended to consult a doctor for a clear diagnosis and targeted treatment under the guidance of the doctor.