Shoulder pain of lung cancer generally refers to shoulder pain caused by apical lung cancer, which is different from general shoulder pain caused by cervical spondylosis or shoulder arthritis, muscle strain, etc. The main difference is that there are obvious differences in the characteristics of pain, accompanying clinical symptoms and imaging examination. 1. Characteristics of pain (1) Pain location: shoulder pain of lung cancer spreads under the armpit and upward and outward, while general shoulder pain is around the shoulder joint or in the anterolateral and dorsal position. (2) Degree of pain: shoulder pain of lung cancer lasts for a long time, and the pain becomes more and more serious as time goes by; general shoulder pain is mostly dull pain, pain during activity or intermittent, and it will not hurt all the time. (3) Pain relieving method: Lung cancer shoulder pain needs to take pain relieving drugs to relieve; general shoulder pain can be relieved by massage, hot compress or moving joints. 2. Accompanying clinical symptoms: Shoulder pain of lung cancer can have symptoms such as Horner’s syndrome due to sympathetic nerve compression, abnormal sensation of ipsilateral shoulder joint and inner side of upper limb due to brachial plexus nerve compression; general shoulder pain can have limitation of shoulder joint activity. 3. Imaging examination: MRI of shoulder joint in shoulder pain of lung cancer shows that the joint part is normal, while CT examination of chest shows that the apical part of lung is occupied; MRI of shoulder joint in shoulder pain in general shows that the joint part is swollen or other abnormal changes. When shoulder pain occurs, one should go to the hospital for clear diagnosis and targeted treatment.