More children and teens are likely to be diagnosed and treated for high blood pressure under new guidelines released today by the American Academy of Pediatrics (AAP).

An estimated 3.5 percent of children and adolescents in the U.S. have hypertension, or abnormally high blood pressure, but experts say the actual prevalence is likely much higher as elevated blood pressure readings often go undetected.

"If there is diagnosis of hypertension, there are many ways we can treat it," Dr. David Kaelber, co-chair of the AAP Subcommittee on Screening and Management of High Blood Pressure in Children, which developed the report, said in a statement. "But because the symptoms are silent, the condition is often overlooked."

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The new guidelines, which are an update to the guidelines released in 2004 by the National Heart, Lung, and Blood Institute that were endorsed by AAP, include new blood pressure tables that are based on normal-weight children. Previously, the tables included blood pressure measurements only in overweight or obese kids and teens, who are at a greater risk of hypertension.

Because of that change, the new blood pressure values are lower than they were before and allow for a more exact classification of blood pressure according to the patient's weight.

"Prevention and early detection are key," said Dr. Joseph Flynn, who co-chaired the subcommittee. "High blood pressure levels tend to carry into adulthood, raising the risks for cardiovascular disease and other problems. By catching the condition early, we are able to work with the family to manage it, whether that's through lifestyle changes, medication, or a combination of treatments."

The committee that developed the new guidelines included 20 experts who reviewed approximately 15,000 articles and studies published since 2004.

If left untreated, uncontrolled high blood pressure can have devastating effects on the body, including damage to the heart, kidneys, and brain.

The report from the AAP also calls on pediatricians to perform routine blood pressure checks at all annual visits. They should follow a simpler screening table that identifies blood pressures needing further evaluation, and start patients on blood pressure-lowering medications if lifestyle changes fail to work or if the child has another condition like diabetes or kidney disease.

Lifestyle changes, including improved diet and increased physical activity, should still be the first line of defense against obesity and high blood pressure, the guidelines recommend.

"These guidelines offer a renewed opportunity for pediatricians to identify and address this important – and often unrecognized – chronic disease in our patients," Kaelber said. "The easy part was developing the new guidelines. Now we begin the harder work of implementing them to help children and adolescents."