Shoulder pain is a frequent symptom in our daily life. For a long time, due to the misunderstanding of shoulder disorders, people easily mistake many shoulder-related pains as “frozen shoulder”. However, according to the statistical analysis of cases, the pain caused by frozen shoulder only accounts for 5%-8% of all shoulder disorders. In many cases, the real “culprit” is “rotator cuff injury”, which accounts for about 50% of shoulder disorders. Therefore, it is important to recognize shoulder joint disorders, make a clear diagnosis, and find the true cause of the disorder in order to achieve a good treatment result. The identification of shoulder-related diseases is inherently difficult, and even orthopedic surgeons are not easily able to make a correct diagnosis without special training. Therefore, it is best to see an orthopedic surgeon or sports medicine specialist at a major hospital to avoid misdiagnosing frozen shoulder and delaying the condition. The shoulder joint is the joint with the largest range of motion in the body, allowing the hand to touch any part of the body. It is because of its flexibility and importance that there is a diversity of conditions that are subject to injury. Although the majority of shoulder patients are middle-aged or older, there is a trend toward younger patients with rotator cuff tears and glenoid labral injuries, mainly due to occupational habits, exercise, and willingness to be improperly protected. Many people lack proper knowledge of shoulder joint diseases, originally rotator cuff injury but treat it as frozen shoulder, thinking that it can be cured by itself without treatment or adopt wrong treatment methods, such as massage and massage, wide range of shoulder joint circular rotation movement, etc. Not only the pain symptoms are not relieved, but also it will aggravate rotator cuff injury, delaying the condition and missing the best time for treatment. So how to identify frozen shoulder or rotator cuff injury? Frozen shoulder is a chronic aseptic inflammatory disease that causes stiffness and adhesions in the shoulder joint, which is characterized by pain around the shoulder joint and limited active and passive movement of the shoulder joint in all directions. Frozen shoulder usually occurs in the habitual shoulder, where the patient has difficulty in washing, combing, dressing, holding and placing objects in high places, and driving, and other daily activities, and the shoulder joint movement is limited. Frozen shoulder is a self-limiting disease, which means that the patient has difficulty in washing, combing, dressing, holding and placing high objects, and driving. It is a self-limiting disease, which means that the pain can be relieved in six months to a year with or without conservative treatment. However, if the symptoms are not relieved for a long time, with pain at night and weakness in the upper extremities, then the patient may be misdiagnosed. The rotator cuff is a cuff-like muscular structure composed of four muscles: supraspinatus, infraspinatus, subscapularis, and teres minor, formed in front, above, and behind the humeral head, which serves to protect the shoulder joint and is responsible for completing the activities of the shoulder joint in all directions. Acute rotator cuff injuries are common in cases such as lifting and pulling heavy objects, throwing, supporting or landing on the shoulder when falling, or being pulled by external forces; chronic strain injuries occur in middle-aged and elderly people who often participate in sports activities, due to the osteophytes of the acromion, which produce impingement and damage to the rotator cuff. The biggest difference between the two is that patients with frozen shoulder are unable to lift their arms with the help of others, while those with rotator cuff injury can lift their arms with the help of others, although they are unable to do so themselves. Patients with frozen shoulder need to do exercises such as pushing, climbing wall lifts, and wide circling to pull apart the adherent tissues, whereas patients with rotator cuff injuries should not exercise or move hard. Once a rotator cuff injury is misdiagnosed as frozen shoulder, not only will it increase the degree of rotator cuff tearing, but also after a long period of misdiagnosis, the rotator cuff muscles will become fatty due to lack of stress. At this time, even if you receive surgical stitches, the muscles have no contraction and the treatment will not be very effective. How to treat Clinically for rotator cuff injury, it is important to consider the different groups of people with the disease, the cause of the disease and the degree of pain. Treatment is also gradual. In the acute phase of rotator cuff injury, rest and recuperation are recommended. Initially, conservative treatment can be carried out: the main conservative treatment methods for rotator cuff injury are local physiotherapy, acupuncture, massage, external application of Chinese herbs or painful point closure, etc. The purpose is to improve the pain symptoms. If the patient does not show signs of improvement after 3 months of conservative treatment, the patient should undergo a review of MRI. If there is no improvement in the degree of rotator cuff tear and the shoulder muscles start to atrophy, the patient should undergo an arthroscopic minimally invasive rotator cuff repair or a surgical procedure to remove the bones of the rotator cuff. For rotator cuff injury caused by trauma, it is easy to take active treatment, and whenever it affects the patient’s function and daily life, arthroscopic minimally invasive surgery should be performed early to reduce the occurrence of sequelae.