Toxic Stress: How the Body's Response Can Harm a Child's Development

Stress is a natural part of life, but stress that occurs constantly or is triggered by multiple sources can take a toll on a child’s health. Toxic stress that children suffer not only shapes their emotional lives as adults but also affects their physical health and life expectancy.

Can Stress Be Helpful or Good?

Stress is the body’s natural response to challenges. It’s what gives us the burst of energy to take a test or the adrenaline to react quickly in dangerous situations. For example, imagine you are hiking in the forest and are confronted with a bear. Your heart races, your muscles tense, and you’re ready to run. That’s your body’s built-in “fight-or-flight” system in action. The body’s stress response is beneficial to help you survive this potentially life-threatening encounter.

However, this stress response is only appropriate and useful if you are actually in the woods with a bear. A problem occurs if “the bear” comes home with you every night; for example, if you are a 5-year-old whose single working parent is struggling with alcoholism. This child experiences stress day after day which can become “toxic stress.”  In these situations, children find themselves freezing, unable to act against a threat, or fawning, developing people pleasing tendencies to avoid conflict.

Stress goes from being helpful and lifesaving to unhelpful and life-damaging. Children are especially vulnerable to this repeated stress activation, as their brains and bodies are in a critical and sensitive period of development.

Three Types of Stress

Stress can be divided into different categories: positive stress, tolerable stress and toxic stress.

1. Positive stress is brief and manageable, often providing motivation to learn and grow. Positive stress is characterized by short increases in heart rate and hormone levels. Examples include meeting new people, learning a new skill or facing a challenge with support from parents or teachers.
2. Tolerable stress is more serious and activates the body’s alert system to a greater degree. Examples include being in a car accident or being admitted to the hospital. If the activation is short-term and supported by relationships with adults who help the child adapt, the brain and other organs recover from what might otherwise be damaging.
3. Toxic stress occurs when a child faces continual activation of the stress response system without sufficient support- such as abuse, neglect, caregiver mental illness or exposure to violence. This kind of stress can alter brain development and increase the risk of future health problems.

What Happens to the Body During Toxic Stress?

When a child experiences toxic stress, the Hypothalamic Pituitary and Adrenal (HPA) hormone axis is over-activated. This results in blood levels of the stress hormone cortisol being higher which can result in long term changes in inflammation and immunity. Studies have shown connections between toxic stress and changes in brain structure. Children exposed to chronic stress are more likely to experience behavior problems and learning impairments and are more vulnerable to infections and illness.

Research from the Adverse Childhood Experiences (ACE) Study have shown a strong link between early stress and later health challenges. Children exposed to multiple adverse experiences have a higher risk of developing conditions like heart disease, diabetes, chronic obstructive pulmonary disease, depression and cancer.