Trauma occurs when one experiences a loss of safety, control, autonomy or self esteem.
A single incident can happen to two different people. But the meaning, significance and impact one puts on the event defines it as trauma. Only you can define your trauma.

The effects of trauma results in post traumatic stress disorder(PTSD). Symptoms of PTSD can include flashbacks, panic attacks, anger outbreaks, insomnia, hypervigilence, fear of being outdoors, claustraphobia, nightmares, generalized anxiety and depression. Traumas include war, rape, physical assault, accidents, witness of suicide or murder, death of a loved one, divorce, illness, bullying to loss of control.