For a small number of people stroke seems to run in the family. However, even if you have a family member who has had a stroke, it does not mean that you will have a stroke. Stroke is very common and many families are affected by it – this may be due to factors such as smoking or eating habits which run in the family – so it's not just your ‘family constitution’. When habits change, the risk of stroke can change too!
If you are worried about a history of stroke in your family you should discuss it with your doctor or practice nurse.