Factors resulting from heredity or natural processes can't be changed. Factors resulting from lifestyle or environment can be modified with a doctor's help. High blood pressure is the most important controllable risk factor for brain attack. Many people believe the effective treatment of high blood pressure is a key reason for the accelerated decline in the death rates for stroke. After high blood pressure, heart disease is the most important risk factor for stroke.
Heart attack is also the major cause of death among survivors of stroke.
In recent years studies have shown cigarette smoking to be an important risk factor for brain attack. The nicotine and carbon monoxide in cigarette smoke damage the cardiovascular system in many ways. The use of oral contraceptives combined with cigarette smoking greatly increases stroke risk. High Red Blood Cell Count. Even a moderate increase in the number of red blood cells thickens the blood and makes clots more likely.