More than half of all children and adolescents in the United States are inadequately hydrated, according to a Harvard study HealthDay reported.

Inadequate hydration couldhave significant repercussions on the physical health, and cognitive and emotional functioning of a child. Researchers found racial/ethnic and gender gaps in hydration status. Black children and adolescents were at higher risk of inadequate hydration than whites; boys were at higher risk than girls.

"These findings are significant because they highlight a potential health issue that has not been given a whole lot of attention in the past," Erica Kenney, lead author of the study and a postdoctoral research fellow in the Department of Social and Behavioral Sciences at Harvard Chan School, said in a statement. "Even though for most of these kids this is not an immediate, dramatic health threat, this is an issue that could really be reducing quality of life and well-being for many, many children and youth."

Drinking enough water is essential for physiological processes such as circulation, metabolism, temperature regulation, and waste removal. Although excessive dehydration is associated with serious health problems, even mild dehydration can cause issues, including headaches, irritability, poorer physical performance, and reduced cognitive functioning.

For the study, researchers used urine osmolality to measure the hydration levels of more than 4,000 children and adolescents, CBS News reported.

They found that a little more than half of all children and adolescents weren't getting enough hydration. Boys were 76 percent more likely than girls, and non-Hispanic blacks were 34 percent more likely than non-Hispanic whites, to be inadequately hydrated.

"The good news is that this is a public health problem with a simple solution," said senior author Steven Gortmaker, professor of the practice of health sociology. "If we can focus on helping children drink more water -- a low-cost, no-calorie beverage -- we can improve their hydration status, which may allow many children to feel better throughout the day and do better in school."

The findings are detailed in the American Journal of Public Health.