The new recommendations call for doctors to begin checking patients for elevated blood pressure at age three during routine office visits. Monitoring height and weight have been standard practices for decades in pediatricians' offices, but the growing problem of obesity calls for additional tests that are often overlooked.

"I think there is still a large proportion of pediatricians and family practitioners who are not routinely measuring blood pressure," said Ronald Portman, M.D., a member of the American Society of Hypertension committee that drew up the new guidelines. The journal Pediatrics will publish the guidelines in its July issue.

The government estimates that 16 percent of U.S. children are overweight, a dramatic increase from three decades ago. Recent statistics suggest that children's blood pressures have risen significantly in the last decade, in large part due to sedentary lifestyle and overeating.

"The real problem is obesity," said Dr. Barbara Alving, acting director of the National Heart, Lung and Blood Institute. "We are setting the stage for our children to develop into really unhealthy adults."

Dr. Bonita Falkner of Thomas Jefferson University, head of the guidelines committee, said that in recent years, doctors have learned that organ damage can occur even in very young children with high blood pressure.

Pediatricians should routinely check their young patients for conditions such as heart enlargement and thickening of the carotid artery.

Better yet, pediatricians should address the issue of weight with patients and their parents to help reduce or prevent the possibility of these problems developing in the first place.