If half of the hand numbness is persistent, it may be caused by intracerebral organic lesions, such as small cerebral infarction, small amount of cerebral hemorrhage, patients can present with acute onset, mostly seen in middle-aged and elderly people, most patients have a history of hypertension, diabetes, hyperlipidemia and cerebral atherosclerosis. If the patient’s symptoms are subacute or chronic, it may be caused by a cranial tumor or encephalitis, and an EEG, cranial CT or cranial MRI may be performed to clarify the diagnosis if necessary. It may also be caused by local nerve compression due to cervical spondylosis, or it may be caused by local nerve entrapment after trauma. Patients with brachial plexus neuritis may also experience the above symptoms and should be treated accordingly for different causes.