High blood pressure affects many Americans but experts say it could be a problem with children.
Researchers at Harvard Medical School compared large groups of children who participated in health surveys in 1994 and 2008.
They found the risk of high blood pressure in children climbed by nearly 30 percent.
Experts say boys were more likely to have higher numbers compared to girls.
African-American children were also at an elevated risk compared to other ethnicities.
Officials say being overweight and eating more salty foods are to blame.