Headache and leg weakness have the following possible causes: 1. Headache and leg weakness may be caused by cold and fever, and patients are advised to take appropriate cold medications to control the symptoms. 2. Headache and leg weakness, if they appear suddenly, need to consider the possibility of acute cerebrovascular disease such as acute cerebral infarction, cerebral hemorrhage, transient ischemic attack, etc. Patients are advised to go to the hospital as soon as possible to improve cranial CT or MRI examination. If it is determined that the headache and leg weakness are caused by acute cerebral infarction, suitable patients need to be given alteplase thrombolytic therapy within 4.5 hours after the onset of the disease.3. Headache and leg weakness may also be caused by intracranial infection or intracranial tumor, and patients are advised to improve cranial magnetic resonance and lumbar puncture examination to clarify the cause.