A |stroke| is caused by the cutting off of the flow of ~blood~ in the cerebral arteries. Its symptoms include |headache|, |paralysis|, difficulty with speech or vision, and possibly unconsciousness. The only treatment a lay person can do is to check for breathing and pulse. If no breathing, begin |mouth|-to-mouth breathing and if no pulse, begin CPR if trained to do so. Get someone to call for help. Do not leave the patient until emergency medical assistance arrives.
