The common causes of pain in the acromion include acromion fracture, subacromial impingement syndrome, etc. The details are as follows: First, acromion fracture: acromion fracture can be caused by violent direct impact around the acromion, and patients will have acromion pain, swelling and limitation of acromion movement, X-ray film can be used to determine the diagnosis, and early immobilization treatment will restore the function of the acromion. Second, subacromial impingement syndrome: the acromion presents type II or type III acromion due to congenital developmental abnormality, with ageing, subacromial impingement syndrome can occur, the lower surface of acromion and the upper surface of rotator cuff are repeatedly worn and impinged, thus producing acromion pain symptoms, accompanied by limited shoulder joint activities and shoulder weakness, diagnosis can be confirmed by X-ray film and MRI. Early arthroscopic surgery to abrade the hyperplastic acromion can lead to the complete disappearance of the acromial pain symptoms, and the shoulder joint strength will be restored.