Sudden numbness or weakness of one side of the face or limb; 2. Sudden blurred vision or blindness, especially unilateral; 3. Aphasia, difficulty speaking or understanding language; 4. Sudden severe headache of unknown origin; 5. Unexplained dizziness, unsteady walking or sudden fall, especially when accompanied by any of the above symptoms; the duration of the above symptoms may be as short as a few seconds. However, regardless of the duration, as long as the above symptoms occur, prompt medical attention should be sought.