There may be the following reasons that can lead to symptoms of pain in the shoulder and arm at the same time: 1. The most common disease that can cause such symptoms is cervical spondylosis, cervical spondylosis and cervical disc herniation, the difference is that cervical spondylosis is bone proliferation, while cervical disc herniation, is a change in the location of cartilage. The onset of cervical spondylosis is relatively slow, while the onset of cervical disc herniation is faster and more urgent. The slow proliferation of bone gradually invades the surrounding soft tissues and most easily compresses the cervical nerves, resulting in painful symptoms in the shoulder and arm or numbness. Especially after overworking the neck or working with the head down for a long time, the symptoms will be aggravated. 2. If this symptom occurs in middle-aged and elderly people, it is most likely caused by frozen shoulder, which mostly occurs in middle-aged people around 50 years old, with obvious symptoms of limited shoulder movement. The painful symptoms occur when the soft tissues around the shoulder joint become adherent and pull on the soft tissues of the arm, which is especially noticeable at night.