To reduce risk factors for adult disease in our society, we must tackle the problem of toxic stress in early childhood. This condition is associated with the excessive release of a stream of hormones whose persistent elevation can disrupt the wiring of the developing brain and the functioning of the immune system. Children who experience toxic stress in early childhood may develop a lifetime of greater susceptibility to stress-related physical illness, such as cardiovascular disease, hypertension, and diabetes, as well as mental health problems, including depression, anxiety disorders, and substance abuse. Reliable, nurturing relationships with adults buffer children from the adverse effects of toxic stress and are essential for healthy brain development. These protective influences can be provided by families, child-care facilities, libraries, schools, neighborhood support networks, and family-friendly places of employment--each of which has a role to play in supporting the healthy development of all children.