Aggressively treating high blood pressure may not be good medicine after age 80, according to a new study reported in the Journal of the American Geriatrics Society (Volume 55, page 383).

In this study, researchers looked at the medical records of more than 4,000 veterans age 80 and older with high blood pressure. Participants who lowered their blood pressure to just below the upper limit of normal -- 139/89 mm Hg -- were less likely to die of any cause over a five-year period than those who reduced their blood pressure to lower levels. This relationship held when the researchers took into account other illnesses that can lead to premature death.

These findings do not contradict current guidelines that recommend lowering blood pressure to below 140/90 mm Hg. But they do suggest that aggressive lowering of blood pressure beyond this level could be harmful for people over age 80, possibly because of reduced blood flow to vital organs.

The potential dangers of lower blood pressure levels in people over age 80 need to be confirmed in randomized, controlled trials before experts recommend less stringent blood-pressure goals for this age group. But if you experience any symptoms of aggressive blood-pressure lowering -- dizziness, weakness, or thinking problems -- tell your doctor, who may then make a change in your treatment regimen.