the greatest risk factor, well that depends because their is quite a few risk factors. it depends where the person is having the stroke. so say someone was having a stroke in the library then you would have to move everything out of the way so they cant hurt themselves and call the ambulance straight away and tell them the signs the person is showing to tell you their having a stroke e.g. face dropping, slowed speech and cant hold their arm up in the air on their own.