• Long-term or frequent rises in cortisol can have negative health consequences. 
• The first study, which looked at 191 full-time day-care children, found that many preschoolers experience increasing levels of cortisol throughout the day, the opposite of how the hormone is produced in most humans.
• In the second study, higher cortisol levels were found in children distressed by their parents’ fighting.
  • Children who become very upset when their parents fight are more likely to develop psychological problems and have higher cortisol levels.
  • Study leader Patrick T. Davies, professor of psychology at the University of Rochester, said in a news release from the journal’s publisher, “Because higher levels of cortisol have been linked to a wide range of mental and physical health difficulties, high levels of cortisol may help explain why children who experience high levels of distress when their parents argue are more likely to experience later health problems.”

More information

The U.S. National Library of Medicine has more about stress.