If there is a bout of pain in the arm, two common causes can be considered: the first cause is inflammation of the tendon sheath caused by long-term strain on the arm, which is a sterile inflammation. You can consider local physiotherapy and hot compresses to improve the symptoms, or you can also use some non-steroidal anti-inflammatory drugs for treatment, such as topical application of Furtalin cream; usually also pay attention to reasonable rest, to avoid cold fatigue. The second possible cause is cervical spondylosis, due to prolonged head down, it is easy to cause cervical spine lesions, which can compress the nerve radiating to the arm, causing a burst of pain symptoms, this situation requires a CT examination of the neck to clarify. If it is a cervical spine lesion, physical therapy traction of the neck can be carried out, and in serious cases, minimally invasive surgery can be considered for treatment.