Suddenly unable to walk, mainly consider the following causes: 1. If there is a sudden inability to walk, for an elderly patient with upper limb mobility disorders, along with slurred speech or crooked mouth, or choking on water, consider that the patient may have acute cerebrovascular disease, such as cerebral infarction or cerebral hemorrhage, and need to go to the hospital to do a cranial MRI examination. 2. If a young patient suddenly appears unable to If the patient has a sudden inability to walk and weakness of the lower extremities, ask the patient if there are any pre-existing triggers, such as lumbar force or a previous lumbar disc herniation, a patient with a previous lumbar disc herniation, when the lumbar posture is not correct, it will suddenly cause nerve damage to one limb that cannot move, manifesting as a sudden inability to walk. 3. If the patient has a history of epilepsy, there are some patients who have focal seizures, show lower limb convulsions, may suddenly appear unable to walk, and need to do cranial EEG examination. The main reasons for the sudden inability to walk can be found in the above mentioned areas.