Blood pressure: The second number matters, too

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Published: October, 2019

Although people tend to focus more on the first number in a blood pressure reading, the second number is also important for predicting heart disease risk. That's according to a study based on 36 million blood pressure readings from more than 1.3 million adults, published in the July 18 New England Journal of Medicine.

Systolic pressure (the first number in a blood pressure reading) measures the force with which the heart pumps blood into the arteries. Diastolic pressure (the second, lower number) reflects the pressure in the arteries when the heart rests between beats. Over eight years, more than 44,000 people in the study had a heart attack or stroke. The risk of those events rose among people with systolic readings of 130 and higher, but also in those with diastolic readings of 80 and higher. The findings are a reminder to pay attention to both numbers in your blood pressure reading, and that for most otherwise healthy people, lower blood pressure is better.

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