PTSD (posttraumatic stress disorder) is a mental health problem that some people develop after experiencing or witnessing a life-threatening event, like combat, a natural disaster, a car accident, or sexual assault.
PTSD can happen to anyone. It is not a sign of weakness. A number of factors can increase the chance that someone will have PTSD, many of which are not under that person’s control. For example, having a very intense or long-lasting traumatic event or getting injured during the event can make it more likely that a person will develop PTSD. PTSD is also more common after certain types of trauma, like combat and sexual assault.
Source : PTSD
For further information, you can look up the link of the source I used for this article.