The common clinical causes of left foot forefoot swelling include trauma, infection, gouty arthritis and aseptic inflammation, etc. It is necessary to go to the hospital and complete all the examinations in order to clarify the cause of the disease. 1. Trauma: there is a clear history of trauma to the left foot, especially in the forefoot, and the swelling is mostly caused by soft tissue contusion and fracture in the forefoot, which is often accompanied by severe pain in the affected area and aggravated by activities. 2. Infection: mostly caused by bacterial infection, there are skin breaks in the left foot, which are caused by improper disinfection treatment after skin breakage, and the patients may have the typical infections of redness, swelling, heat and pain, and even abscesses may be formed. 3. Gouty arthritis: related to excessive uric acid in the body, urate deposition in the forefoot joints and surrounding tissues, which can lead to localized swelling. 4. Aseptic inflammation: the more common plantar fasciitis, mostly related to the left foot trauma, strain and cold, localized in addition to swelling, mostly accompanied by pain. It is recommended that patients go to the hospital, improve the auxiliary examination, in order to clarify the cause of the disease, the professional physician for the cause of the corresponding treatment.