Left arm pain occurs for the following common reasons: 1. Left arm muscle strain, heavy physical labor will cause serious strain on the left upper limb muscles, the patient will have upper limb soreness, pain symptoms, accompanied by left upper limb weakness performance. After rest, massage and hot compress treatment, the symptoms will disappear completely without residual sequelae. 2, cervical spondylosis, cervical disc protrusion to the left side, compression of the left upper limb nerve, the patient will have left upper limb radiated pain symptoms, the disease can cause left upper limb muscle atrophy when the course is longer, there will be left upper limb weakness. After cervical traction and surgical treatment, the herniated disc can be released from compression and the pain symptoms of the left upper limb can be relieved. Treatment through the above methods can significantly improve the symptoms of left upper limb pain, and attention should be paid to protecting the cervical spine and left upper limb muscles in ordinary life to avoid injury, compression and fatigue.