The first thing to consider is cerebrovascular disease when there is numbness on one side of the body. When this happens, it is important to consult the emergency department or neurology department of the hospital immediately, and the doctor will make a preliminary judgment by examining the body and doing a CT examination of the head. If bleeding is ruled out, it is considered to be caused by cerebral infarction, which requires immediate consultation and treatment. Patients with cerebral infarction usually have some risk factors for cerebrovascular disease, such as hypertension, diabetes, hyperlipidemia, and poor lifestyles, such as smoking and alcohol consumption.