Researchers from South Korea conducted a scoping review—a systematic look across many studies—to understand how scientists measure stress in children through biological markers. The review examined 57 studies published between 2005 and 2025, focusing on typically developing children (those without diagnosed conditions) in regular daily life.
The study distinguished between two types of stress: acute stress (short, sudden events like a difficult exam or argument) and chronic stress (ongoing pressure, like persistent family conflict or school demands). Understanding which type a child experiences matters because they affect the body differently.
Cortisol sampling has become the main way to track childhood stress
The hormone cortisol—released when the body feels stressed—emerged as the most commonly measured biological indicator. Between 2015 and 2019, researchers increasingly used repeated daily cortisol samples (often saliva tests collected multiple times throughout a day) to track how stress fluctuates in children's daily lives. This method gained traction because it's non-invasive and can show patterns over time, though the review noted a slight decline in new cortisol studies since 2020.
Research focuses more on acute stress in older primary students
The review found that studies of acute stress (like exam anxiety) were far more common than studies of chronic stress. Acute stress research typically involved children in upper primary years (roughly ages 7–11), while chronic stress research more often focused on younger preschool-aged children. This means scientists know less about how ongoing, day-to-day pressures affect older primary school children—a gap particularly relevant for Singapore families managing the Primary School Leaving Examination years.
Major blind spots remain in stress research
Beyond cortisol and basic nervous system measures, biological markers remain limited. The review found very few studies using brain-imaging or immune-system indicators to assess childhood stress, suggesting these areas need further investigation. Additionally, while cortisol sampling increased sharply from 2015–2019, fewer new studies have emerged in recent years, indicating the field may be consolidating methods rather than expanding them.
Help your family understand stress more completely
- Request cortisol or stress screening if your child shows persistent anxiety or behavioural changes; this biological measure can complement observations of mood and school performance.
- Recognise that preschoolers and primary students experience different stress patterns—younger children face more chronic pressures, while older primary students often encounter acute exam-related stress.
- Note that cortisol sampling through saliva is now a standard, non-invasive method if a school or healthcare provider recommends stress assessment.