Why nighttime blood pressure doesn't always drop

Most people's blood pressure falls by 10 to 20 per cent while they sleep, giving the heart and blood vessels a chance to recover. But for some people, that nighttime dip never happens. Known as "non-dippers," these individuals face a higher risk of heart disease, stroke, kidney disease and premature death.

Now, researchers at the University of Waterloo have identified a possible reason why.