Pain in the lower and middle part of the calf fibula may be caused by physiological factors such as over-exercise, or it may be caused by other factors such as fibula fracture, soft tissue lesions, and tumors. 1. Physiological factors: if over-exercise, over-exertion and over-activity of the lower limbs, pain in the lower and middle part of the calf fibula may occur. 2. Fibula fracture: If there is a traumatic stimulus, or there is a fall, etc., it may lead to fibula fracture, and there will be pain in the middle and lower part of the calf fibula. Individual fractures of the fibula are not very common, and individual fractures of the lower and middle fibula can also occur. 3. Soft tissue lesions: If the muscles, fascia, ligaments, etc. of the lower and middle calf fibula are damaged and become diseased, this may also lead to pain. 4. Others: pain in the lower and middle calf fibula may also be related to bone tumor, which causes pain due to the local compression caused by the production of a mass. There are many reasons for the pain in the lower and middle part of the calf fibula, and it is recommended that patients actively seek medical treatment when the symptoms cannot be relieved, so as to avoid delays in the condition.