The number of Americans with hypertension, or high blood pressure rose by 4 percent in recent years. At the same time, more people with hypertension are aware that they have the condition.

Researchers from the U.S. National Heart, Lung and Blood Institute compared the hypertension findings of two National Health and Nutrition Examination surveys, one which ran from 1988 and 1994 and the other which ran from 1999 to 2004. The first survey included 16,351 participants and the second 14,430 participants. The National Health and Nutrition Survey evaluates a nationally representative sample of the U.S. population.

The good news is that awareness increased among participants with hypertention from 68.5% to 71.8%. The percentage of Americans with high blood pressure increased from 24.4% in the first group to 28.9% in the second group. The treatment rates across race and gender also increased from 53.1% to 61.4%. Control rates increased from 26.1% to 35.1%, according to the study published today in Hypertension: Journal of the American Heart Association.

High blood pressure is a serious condition that can lead to coronary heart disease, heart failure, stroke, kidney failure and other serious health problems. There are several risk factors that contribute to hypertension, such as smoking, alcohol use, excessive salt in diet, sedentary lifestyle, obesity and family history.

According to recent estimates, about one in three U.S. adults has high blood pressure, but because sometimes there are no symptoms, nearly one-third of these people are unaware they have it.