American emergency rooms are treating more people for high blood pressure, a group of doctors told the American Heart Association on Tuesday. The number of emergency hospital visits for what's called "essential hypertension" — high blood pressure with no known cause — climbed 25 percent between 2006 and 2011.

In that same time, however, more people with hypertension who go to hospitals are surviving and leaving the same day. Thirty-six percent fewer people died over the same years and 15 percent fewer were admitted, according to a news release on the findings, presented to the American Heart Association's High Blood Pressure Research Scientific Sessions. "The decrease in admissions and deaths may be due to emergency room and hospital physicians becoming more skilled at treating high blood pressure," said lead author of the associated study, Dr. Sourabh Aggarwal, of Western Michigan University. "But there is still a large unmet need for patients to have better help controlling their blood pressure in the outpatient setting."

The researchers poured over a massive dataset of 3.9 million emergency room visits, tracking the number of people who ended up there with high blood pressure. The doctors did not look into why the patients ended up in the ER in the first place. Likely, the high blood pressure would not have been the main reason the patients went to the hospital. Hypertension is a "silent killer" with few symptoms, leaving victims vulnerable to its potentially fatal effects: stroke, heart attack, and heart failure.

The doctors are blaming themselves for the sharp increase of patients with high blood pressure. The statistics show "we are not doing a good job in controlling high blood pressure in the outpatient setting," Aggarwal said in the statement. "We need better high blood pressure care in this setting." According to the American Heart Association, more than 76 million American adults have hypertension — that is, having a systolic blood pressure higher than 140. Systolic blood pressure higher than 180 is a "hypertensive crisis."

Source: Aggarwal S, Agrawal Y, Gupta V. American Heart Association. 2014.