Nearly Half Of U.S. Adults May Have High Blood Pressure Under New AHA Guidelines

ANAHEIM (CBS SF) -- Under new health guidelines for hypertension, nearly half of all adults in the United States suffer from high blood pressure and are at risk of major health problems.

The American Heart Association announced the new rules at a conference Monday based on a study published in the AHA journal, "Hypertension."

High blood pressure is now defined as 130/80, a change from the previous reading of 140/90. Normal is defined as 120/80 or less. Anything above is now considered "elevated" or "Stage 1" or "Stage 2."

In terms of lives, the change translates to a 14% increases in the number of adults classified with high blood pressure. One in five may need medication.

High blood pressure is caused when the force of blood pushing against vessel walls is too high. There are no obvious symptoms, which is why it is often called, "the silent killer."

Kenneth Jamerson, M.D., Ph.D., professor of internal medicine and hypertension specialist at the University of Michigan was one of nearly two dozen medical experts who wrote the new guidelines. He says they will prevent disease by encouraging early treatment.

"Yes, we will label more people hypertensive and give more medication, but we will save lives and money by preventing more strokes, cardiovascular events and kidney failure," he said, in a statement.

High blood pressure has even associated dementia.

The guidelines recommend lifestyle changes, eating a healthy, low-sodium diet, rich in potassium -- bananas, potatoes, avocados, leafy green vegetables -- weight loss, exercise, and cutting out alcohol and tobacco.