Frozen shoulder is a broad concept and to date most physicians still attribute shoulder pain to frozen shoulder and treat it accordingly. However, according to the Sports Medicine Association, what is often referred to as frozen shoulder is actually adhesive capsulitis, which is a self-limiting condition that does not require specific treatment and has a low incidence. There are many causes of shoulder pain including rotator cuff injury, rotator cuff impingement, shoulder instability and even cervical spondylosis that can cause shoulder discomfort. It is clear that there is still a great deal of misunderstanding about shoulder disorders in our lives. Some patients may delay treatment and may even cause shoulder joint dysfunction, which can seriously affect their daily life. How to correctly understand shoulder joint disorders? First of all, it is important to have a certain understanding of the shoulder joint. The shoulder joint is a very complex joint. Simply put, it is a multi-axis ball and socket joint, consisting of the humeral head and the scapular glenoid forming the glenohumeral joint. The humeral head is large while the scapular fossa is shallow, and the surrounding joint capsule is weakly restricted, so the shoulder joint is the most mobile and flexible joint in the human body. Some tendons (rotator cuff) end at the greater tuberosity of the humerus and wrap around the humeral head from the front, top and back of the shoulder joint to strengthen the stability of the shoulder joint. The joint capsule overlays the rotator cuff to reduce impingement friction between the rotator cuff and the rostral shoulder arch above it. Because of the high mobility of the shoulder joint, there exists an anatomical basis for susceptibility to shoulder joint disease. Second, we need to properly understand shoulder disorders. Statistically, the highest incidence of shoulder disorders is rotator cuff injury, which accounts for 30-40% of shoulder disorders. The symptoms of rotator cuff tears are similar to those of acromioclavicular impingement syndrome, but they are also accompanied by shoulder abduction weakness. Athletes, those who lift heavy objects, and those who suffer from traumatic injuries are prone to rotator cuff injuries. Typical symptoms are pain in the neck and shoulder at night, pain in the arm when lifting; not daring to sleep on the affected side, or even being awakened by pain; and weakness in the shoulder joint during abduction, supination or posterior extension, which can seriously affect daily life. Shoulder impingement is a condition in which the acromion and subacromial bursa tissues are impinged and squeezed against the rotator cuff tissues during shoulder abduction and supination, causing shoulder joint pain and supination dysfunction. In general, impingement and rotator cuff lesions occur more often in older individuals and throwing athletes. The patient’s shoulder pain gradually worsens when throwing or lifting the arm. The pain often radiates to the proximal lateral and mid-arm areas. If treatment is delayed, the patient may experience severe muscle atrophy and severe pain that affects sleep; if left to develop, it may lead to shoulder tendon rupture at a later stage, seriously affecting the patient’s function and life. The third most prevalent shoulder joint disease is shoulder instability. Due to trauma the shoulder joint is prone to dislocation or subluxation. The affected shoulder will produce pain, impaired movement, limited function, and in some cases, habitual shoulder dislocation will occur. Without timely treatment, bone defects and joint surface destruction can occur, making later treatment difficult. The combined incidence of the first three diseases accounts for almost 70% or more of shoulder joint diseases. In addition, there are many other diseases that cause shoulder joint pain, such as acromioclavicular arthritis, biceps tendonitis and calcific supraspinatus tendonitis. Such so-called frozen shoulder diseases account for a much smaller percentage of shoulder joint diseases. It can be seen that when thinking that shoulder pain is frozen shoulder, we are likely to unknowingly enter the misunderstanding of shoulder joint diseases, which is not beneficial for treatment. Shoulder disorders are complex and diverse, and the most appropriate treatment must be taken after diagnosis by a shoulder specialist, otherwise the best time for treatment will be missed.