The rate of high blood pressure among children has risen nearly 30 percent in 13 years due to growing waistlines and high-sodium diets.

High blood pressure is epidemic in the developed world, especially in the United States, but what’s truly alarming is just how many children are affected. New research published in the the American Heart Association journal Hypertension found that the risk of elevated blood pressure has risen for children and adolescents by 27 percent over a 13-year period.

Across the board, many children also eat more than the Reference Daily Intake (RDI) guidelines for sodium, which is a major culprit in high blood pressure, or hypertension. That, coupled with children’s growing waistlines, shows that a number of risk factors for poor heart health are putting young people in danger.

The statistics are even more dire for some children of color. African-American children in the study group had a 28 percent greater risk of elevated blood pressure than their non-Hispanic white peers.

The researchers examined data on more than 3,200 children ages 8 to 17 in the National Health and Nutrition Examination Survey (NHANES) III from 1988 to 1994, and on more than 8,300 children of the same age in a NHANES follow-up study from 1999 to 2008.

Pinpointing a single cause of hypertension is difficult, but you can still determine your risk based on factors such as age, diet, and physical activity level. A professional diagnostic test can provide the most insight, but knowing what to avoid will put you and your family in control.

“High blood pressure is dangerous in part because many people don’t know they have it,” Dr. Bernard Rosner, lead study author and a professor of medicine at the Harvard Medical School, said in a press release. “It’s a very sneaky thing. Blood pressure has to be measured regularly to keep on top of it.”

Once you know that a problem exists, you’ll be able to tackle it head-on.

There are multiple ways to manage high blood pressure, but some of the most effective steps are also the easiest. Focus on preventative ways to lower blood pressure as a family.

If your child has hypertension, take a look at your family as a whole. Could you all be exercising more? Switching to a low-sodium diet? A medical professional can give you advice to help lower your risk, but a few baby steps will go a long way toward improving your health.

“Everyone expects sodium intake will continue to go up,” Rosner said. “It seems there’s been a little bit of listening to dietary recommendations, but not a lot.”

In the study group, children who ate the most salt were 36 percent more likely to have high blood pressure than their peers who ate the least. But the problem, as the researchers point out, is widespread.

Start snacking on foods low in sodium like fresh fruits and vegetables with dip so that your child can follow suit. Check the labels on the food you buy for sodium content so you and your family can fight high blood pressure at the source.