Pain in the left forefoot when walking can be caused by the following reasons: first, metatarsal head infection, metatarsal head infection can have pain at the metatarsal head of the forefoot when walking, which should be diagnosed and treated at an early stage by examining X-rays and CT of the metatarsal bones; second, fatigue fractures of the metatarsal bones, when fatigue fractures occur in the bones of the metatarsal bones due to chronic strain, which can have pain at the metatarsal bones of the forefoot when walking. Third, tumors of the metatarsal bones, when there is a tumor in the metatarsal bones can also have pain in the forefoot when walking, which can be accompanied by local symptoms, such as pressure pain or systemic symptoms, such as wasting or low fever, when the foot MRI and CT should be examined to diagnose; fourth, plantar fasciitis, plantar fasciitis can have pain in the forefoot when walking, often in the cold, the pain worsens when exerting. The pain can be aggravated by cold and exertion, and there can be significant pain in the morning, which should be diagnosed by early physical examination and examination to exclude other diseases.