Upper arm muscle numbness has the following reasons: First, common causes of bone surgery diseases, such as cervical spondylosis or frozen shoulder, will lead to muscle soreness and numbness around the arm, swelling and pain, such as peripheral nerve root pain problems. Second, common arm muscle numbness in the upper arm is also due to incomplete blood supply to the cerebrovascular system, so it will affect the local blood supply, resulting in arm muscle soreness and numbness. Third, when the heart is seriously ischemic, it will also cause the clinical symptoms of left arm muscle soreness and numbness and pain. Fourth, excessive exercise when anaerobic glycolysis, at this time will allow the body to accumulate too much lactic acid, lactic acid is easy to deposit in the upper arm and other muscular areas, thus leading to muscle numbness and pain. Fifth, when heat stroke occurs rhabdomyolysis, numbness and pain in the arm muscles will also occur.