Some people only have high blood pressure at night, while their levels are fine during the day.
And according to UPI, Japanese researchers say that phenomena puts them at a significantly greater risk for heart disease.
The Centers for Disease Control and Prevention estimates nearly half of all adults in the United States -- or 108 million people -- have high blood pressure.
The researchers say if a person's nighttime systolic blood pressure is 20 mm. Hg above daytime readings, they are at 18% at greater risk for heart disease.
They also said that same rise in nighttime blood pressure also increases a person's risk for heart failure by 25%.
