The arm epidermis hurts when you touch it mostly belongs to sensory hypersensitivity, clinically, it is mainly seen in spinal cord disease, spinal cord root lesions, herpes zoster, neuritis, hysteria.1, spinal cord disease is most commonly seen in spinal cord tuberculosis, the patient has a past history of tuberculosis, in addition to the sensory hypersensitivity, it can also be manifested in limb weakness, unsteady walking, emaciation, fatigue, low-grade fever, night sweats, and so on. Diseases of the posterior spinal root are commonly due to occupational compression of the posterior heel of the spinal cord, posterior spinal cord heel inflammation, which is mainly manifested by numbness and nociceptive hypersensitivity. Herpes zoster is mostly caused by herpes zoster virus infection, in addition to sensory hypersensitivity can also be manifested with fever, malaise, localized skin edema can be seen.2. Neuritis is mostly caused by drugs, heavy metal poisoning, diabetes, autoimmune diseases, mainly manifested as sensory hypersensitivity or hypesthesia, and the patients are often accompanied by muscular atrophy and limb weakness. Hysteria is mostly seen in female patients, often induced by nervousness or anger, auxiliary examination of the manifestations of no organic lesions, emotional stabilization of the symptoms can disappear on their own.