Pain in the middle finger of the left foot, the following causes are common: First, left foot trauma: acute sprain of the middle finger of the left foot can occur during strenuous exercise, the patient will have swelling, pain and limited movement of the middle finger of the left foot, the patient can not walk with weight or participate in sports, and in serious cases, it can cause local fracture and dislocation, and the diagnosis can be confirmed by taking X-ray. Second, degenerative changes in the left middle finger joint: mainly seen in elderly patients, the patient will show symptoms of pain in the left middle finger, accompanied by limited movement, joint hyperplasia, joint deformation, etc. In serious cases, it will also affect normal walking and sports, and the X-ray will reveal joint space narrowing, serious joint osteophytes, and hardening of the joint surface. After early diagnosis and timely treatment, the painful symptoms of the left middle finger can be relieved quickly.