The concept of a normal blood pressure has fallen strikingly as doctors learn what it takes to preserve good health.

Hypertension, once known as the “silent killer,” is now not so silent.

Through campaigns urging doctors to check patients’ pressure at every visit, most cases have been detected. Although treatment has been prescribed for nearly all people known to have blood pressures consistently above 140/90 -- now called the high end of normal -- up to half of patients still have elevated pressures.

While weight loss and improvements in diet and exercise habits can indeed help people lower an elevated pressure, “most people can’t adjust their lifestyles enough to normalize their blood pressure,” Dr. Moser said in an interview. “Most people need help from medication, notably a diuretic in combination with one or two other drugs. The majority of patients don’t get their pressures to normal without such a combination.”

One of the main problems with a drug-free approach is the difficulty many patients have in adopting and sticking with a diet and exercise program that can significantly lower their pressure.