Most brain functions are located in well-defined areas. So the symptoms of a stroke are influenced more by the location of reduced blood flow than by its cause. Stroke should be suspected when faced with:
Sudden numbness or weakness on one side of the body.
Visual disturbances, such as loss of sight in one eye or one side of the visual field, or double vision.
While a sudden and very intense headache can be a symptom, strokes generally occur without any pain. This is one of the reasons why their diagnosis is often delayed. The person suffering a stroke may not be aware of the problem and so someone close to them must realise what is happening and seek help.