Adverse Childhood Experiences
They are potentially traumatic events that occur in childhood from 0-17 years.
For example:
experiencing violence, abuse, or neglect
witnessing violence in the home or community
having a family member attempt or die by suicide
Also included are aspects of the child’s environment that can undermine their sense of safety, stability, and bonding, such as growing up in a household with:

substance use problems
mental health problems
instability due to parental separation or household members being in jail or prison
ACEs can cause or lead one to have chronic health problems, mental illness, and substance abuse problems. ACEs can also have a negative impact on a persons ability to do well in education, jobs, and earning capabilities. ACEs can be prevented. Education & Awareness on this issue is KEY!

The examples given here are most certainly not an exhaustive one. There are many other traumatic experiences that could impact health and wellbeing.