Suddenly very sore arms may be a long time in a fixed position, cold stimulation and other physiological reasons, may also be cervical spondylosis, muscle strain and other pathological reasons. 1. Physiological reasons: the arm is in a fixed position for a long time, which will lead to fatigue injury of the arm muscles, arm muscle spasm, resulting in the accumulation of lactic acid and other metabolites, stimulation of the nerve root, and soreness symptoms; prolonged exposure to the cold environment will lead to tonic contraction of the arm muscles or spasms, which may also cause the above symptoms. 2. Pathological reasons: cervical spine due to degenerative lesions cervical spondylosis, there will be cervical intervertebral disc dehydration lesions, which may lead to peripheral nerve compression, there may also be a sudden soreness of the arm. Strains in the muscles of the arm area, which can lead to the breaking of muscle fibers and the freeing of intracellular substances such as hemoglobin and erythrocytes in the myocytes into the interstitial spaces of the cells, may also present the above symptoms. Based on the symptoms of sudden very sore arms alone sometimes can not accurately determine the cause, but also need to be combined with the characteristics of the medical history, other test results in order to make accurate judgments, it is recommended to clarify the cause of the disease under the guidance of a doctor.