Aug. 6, 2019&mdash;Every blood pressure reading comes with two numbers, such as 120/80 mm Hg. Systolic pressure&mdash;the top number&mdash;measures how hard the heart pumps blood into the arteries. Diastolic pressure&mdash;the bottom number&mdash;measures the pressure on the arteries when the heart rests between beats. 
Together they tell a story about your heart health. But that second number sometimes gets shrugged off by risk assessment tools. Now a new study of more than a million people confirms that both numbers matter if you want to protect your health. 
Heart-healthy from top to bottom
Past studies have shown that, of the two parts of a blood pressure reading, high systolic pressure was more likely to result in a heart attack or stroke. As a result, doctors have often focused on the first number and ignored the second. 
But a recent study suggests they're both important. 
It looked at more than 36 million blood pressure readings from 1.3 million people. Like other studies, it found that high systolic pressure was a stronger risk factor for heart attack or stroke. But a high diastolic pressure number also raised both risks significantly. 
That was true no matter how high blood pressure was defined: as 140/90 (according to older guidelines) or as 130/80 (according to newer guidelines from the <a target="_blank" href="https://www.netreturns.biz/healthinfo/bouncelink.aspx?shortcut=cardiology">American College of Cardiology</a> and <a target="_blank" href="https://www.netreturns.biz/healthinfo/bouncelink.aspx?shortcut=aha"> American Heart Association</a>).
The takeaway: It's crucial to work with your doctor to keep both blood pressure numbers in a healthy range. 
The study appeared in <a target="_blank" href="https://www.nejm.org/doi/full/10.1056/NEJMoa1803180">The New England Journal of Medicine</a>. 
Need a blood pressure test? 
Learn more about <a href="[BASEDOMAIN]/healthinfo/Story.aspx?StoryID=afc19cb1-5f88-4269-ae5b-15f4e212e50a"> how blood pressure is measured</a>. And read tips on how to get the most accurate reading.

Blood pressure: Both numbers matter

No matter which number you look at, high blood pressure can have life-threatening consequences.