Pain at the base of the left big toe can be caused by plantar fasciitis, gout and external factors. 1. Plantar fasciitis: pain in the big toe after walking more is mainly due to the fact that the big toe exerts more force when walking, so the ligaments and muscles around the big toe are susceptible to soft tissue injuries, and thus pain will occur. 2. Gout: Gout is a form of arthritis that causes joint pain, redness, swelling and inflammation, mainly due to the deposition of urate in the joint cavity, which causes joint pain, most commonly in the root of the big toe. 3. External factors: If the shoes are too tight for a long time, the pressure and friction of the upper part of the shoes will cause pain at the root of the left big toe. It is recommended to go to a regular hospital for examination, the doctor will be based on clinical symptoms to give judgment, clear cause of the disease in time to treat the cause.