-- Affects as many as 4 million children in the U.S. -- Is more frequent and more severe in black families than in whites. -- If untreated, can lead to heart failure and death. Risk factors include obesity and having a parent with high blood pressure. All children 3 and older should have annual blood pressure checks. Doctors should evaluate the readings with charts that indicate normal blood pressure by age, gender and height. Sources: Johns Hopkins Children's Hospital researchers. American Heart Association 