Nearly half of all adults in the US now have high blood pressure, according to new guidelines released by the American Heart Association. 

High blood pressure used to be considered anything higher than 140 over 90. The new guidelines drop those numbers to 130 over 80. 

The change means nearly half of all Americans could now be diagnosed with the "silent killer."

Dr. Allen Jeremias, a cardiologist at St. Francis Hospital, says people will now become more aware of their blood pressure and begin to make lifestyle modifications. 

Doctors stress that eating healthy and exercise is best to keep blood pressure low. They also recommend that people check their blood pressure regularly at home with a cuff that can easily be purchased at any pharmacy.