The American Heart Association and the American College of Cardiology just lowered the threshold for high blood pressure to 130/80 millimeters of mercury, and now 46% of Americans - up from 32% - fall in the danger zone.
For the first time since 2003, the American Heart Association has redefined high blood pressure.
The findings mean that an additional 14% of USA adults, or about 30 million people, will now be diagnosed with high blood pressure, bringing the total number to 100 million people living with the condition in the U.S.
Experts expect the new guidelines will greatly impact younger people, with high blood pressure expected to triple among men under 45 and double among women under 45.
"We want to be straight with people - if you already have a doubling of risk, you need to know about it". Normal is defined as 120/80 or less.
The normal limit for blood pressure is considered 120 for systolic, or how much pressure the blood places on the artery walls when the heart beats, and 80 for diastolic, which is measured between beats. Anything above is now considered "elevated" or "Stage 1" or "Stage 2".
Concerns about those side effects, as well as the fact that the close monitoring seen in a clinical trial is hard to replicate, led the AHA, ACC and other groups to select the 130 systolic blood pressure target.
The new guidelines eliminate the prehypertension category.
"High blood pressure is called the silent killer because it usually has no signs or symptoms to go with it", says Dr. Calvin.
Dr. Larry Gordon from Aspirus said the association most likely made the changes to be proactive and lower the risk of people being diagnosed with more serious illnesses later on. But only a small percentage of those patients will be prescribed anti-hypertensive medication, the association said.
High blood pressure accounts for the second-largest number of preventable heart disease and stroke deaths in the United States, second only to smoking.