Frozen shoulder is also known as periarthritis of the shoulder joint, also known as frozen shoulder or frozen shoulder, and is more common in patients over 50 years old, more women than men, so Japanese scholars also call it “fifty shoulder”. According to Chinese medicine, this disease is mostly caused by the wind and cold in the shoulder, so it is also known as “Leaky Shoulder Wind”. A complete shoulder joint movement is mainly done by four joints, namely the glenohumeral joint, acromioclavicular joint, sternoclavicular joint and scapulothoracic wall joint, and frozen shoulder mainly occurs in the glenohumeral joint. It is characterized by the gradual onset of pain and limitation of joint movement, which is a specific clinical process, i.e., when the pain and limitation of shoulder movement reach a certain level, they do not continue to develop, and the pain gradually decreases and disappears, and the movement of the joint gradually recovers, but some patients do not recover completely. This clinical course may last from a few weeks to several years. There is a complex process between the early changes in frozen shoulder and the late changes in frozen shoulder that is still not well understood. There are 3 features in the overall pathogenesis of frozen shoulder: 1. The soft tissues surrounding the joint capsule are eventually invaded. 2, The development of lesions is not uniform, not all tissues have equal pathological changes. 3, The progression of pathological changes is reversible. By mastering the above pathological changes and the three characteristics, we have a deeper understanding of frozen shoulder, and it is easier to understand the process of changes in the clinical symptoms of frozen shoulder. Frozen shoulder rarely develops twice in one shoulder joint. The age of onset of frozen shoulder corresponds to the age at which severe degeneration of the shoulder joint occurs. Weaker individuals, such as those with metabolic diseases, malnutrition, heart disease, and menopausal syndrome, experience more shoulder degeneration than healthy individuals and are therefore more likely to develop the disease. Patients usually have no history of trauma, or have a very minor trauma to the shoulder or upper arm, and gradually the shoulder joint and its surrounding muscles become painful, weak, and impaired in movement. Pain is the most obvious symptom and has a persistent nature. It can be spontaneously aggravated at night and interfere with sleep. Pain and muscle spasm can be confined to the shoulder joint, but can also radiate upward to the back of the head, downward to the wrist and fingers; some take the shoulder joint as the axis forward to the chest, backward to the scapula area, and some radiate to the triceps, deltoid or biceps area, at which point it should be carefully examined to distinguish it from cervical spondylosis and heart disease. The entire course of frozen shoulder can be divided into three phases: the beginning phase, the freezing phase, and the thawing phase. The initial phase is characterized by discomfort and a binding sensation in the shoulder joint. The pain may be limited to the anterolateral aspect of the shoulder joint or may extend to the point of resistance of the deltoid muscle. The shoulder joint gradually becomes stiff and painful. The pain during the freezing phase can be mild or severe, and is characterized by increased pain at night which affects the patient’s sleep. When the shoulder joint moves, it can cause strong pain and muscle spasm, so that the movement of the shoulder joint can be completely restricted, as if the hand is frozen. The pain may be mild during the thawing phase, the shoulder joint may gradually relax, and the glenohumeral joint may gradually regain more movement, but in some patients, the shoulder joint may only partially recover or become tense and immobile. Blood sedimentation, anti-chain “O” and latex tests are all negative. The pathological changes can be divided into four categories according to the different sites of pathogenesis: 1. Periprosthetic bursal lesions: including exudative inflammation, adhesions, occlusion and calcium deposition of the bursa; they can involve the subacromial bursa, the subdeltoid bursa and the bursa on the rostral process. 2. Glenohumeral joint cavity lesions: “frozen shoulder or secondary adhesive capsulitis” can have fibrinous exudate in the cavity in the early stage, and joint cavity adhesions and volume reduction in the late stage. 3. Degenerative lesions of tendons and tendon sheaths: biceps longus tendinitis and tenosynovitis, supraspinatus tendinitis (painful arc syndrome), calcific tendinitis, rotator cuff rupture and partial rupture, impingement syndrome, etc. 4.Other periapical lesions: such as rostral synostosis, shoulder fibrillitis, suprascapular nerve entrapment, acromioclavicular joint lesion, etc.