Arm and hand numbness may be caused by acute cerebrovascular disease, cervical spondylosis, brachial plexus neuritis, and peripheral neuropathy, as follows: I. Acute cerebrovascular disease: Acute cerebrovascular disease is the most common cause of arm and hand numbness. If a patient suddenly develops symptoms of numbness on one side of the arm and hand, the presence of acute cerebral hemorrhage, cerebral infarction, or transient ischemic attack should be suspected. At this time, patients should quickly go to the hospital, head CT, MRI examination to exclude acute cerebrovascular lesions. Second, cervical spondylosis: cervical spondylosis is a more common cause of arm and hand numbness, cervical spondylosis mainly causes bilateral symptoms of arm and hand numbness, and in severe cases will lead to symptoms of limb weakness. Third, peripheral neuropathy: peripheral neuropathy is easy to cause arm and hand numbness common causes, such conditions are mostly due to diabetes, vitamin deficiency, poisoning, drug factors.