There are many causes of numbness in half of the body, as follows: 1. Acute cerebrovascular disease. For example, acute cerebral infarction, cerebral hemorrhage. Acute cerebral infarction mostly occurs at night, which will result in crookedness of the mouth, dizziness, headache and hemiparesis. Once the attack occurs, immediate medical attention is needed to avoid leaving sequelae. Acute cerebral hemorrhage will cause dizziness and vomiting, limb paralysis and loss of consciousness. 2. Intracranial tumor. The tumor will compress the nerves for a long time and cause numbness in half of the torso, which requires surgery to remove the tumor and contact the symptoms of nerve compression. 3. Subdural hematoma. There will be dizziness, headache and vomiting, numbness of one side of the limb, memory loss, acute subdural hematoma with large bleeding volume needs surgical treatment and craniotomy for hematoma removal. Less severe symptoms require medication, such as atorvastatin.