Sudden pain in the instep without trauma includes soft tissue damage, dice bone syndrome, gout, peroneal nerve palsy and so on. 1. Soft tissue damage: ill-fitting shoes or improper exercise may cause damage to tendons, ligaments and other tissues of the dorsum of the foot, causing pain in the dorsum of the foot. 2. Dice Bone Syndrome: pain caused by misalignment or dislocation of the dice bone and damage to the nearby ligaments or muscles, with pain aggravated when the back of the foot is downward and weakened when the back of the foot is upward. 3. Gout: Gout attack caused by excessive purine intake or heavy drinking, manifested by pain on the back of the foot, red and swollen joints and high skin temperature. 4. Peroneal nerve palsy: when there is a history of peroneal neuritis, and the calf is attacked by cold or subjected to prolonged stress, the peroneal nerve will be compressed or pulled to cause dorsal pain, and the foot will drop down. If the pain in the back of the foot is severe or accompanied by activity limitation, it is recommended to go to the hospital in time, with the help of the doctor for regular treatment.