Numbness on the left side of the body is considered to be caused by acute cerebrovascular disease, which is usually located in the thalamus or cerebral bridge and can cause numbness in the lateral limbs. When this situation occurs, the patient must promptly consult a hospital and have a CT examination of the head, and if the CT does not see the infarct foci, it is also caused by cerebral infarction, in case of excluding bleeding. Because the CT has not yet been visualized, active treatment should be given. If it is within the time window of thrombolysis, intravenous thrombolysis can be given; if it is not within the time window of thrombolysis or there is no indication for thrombolysis, treatment of fibrin-lowering, anticoagulation, antiplatelet aggregation and cerebral protection should be given to prevent further aggravation of the patient’s neurological deficit.