Having PTSD is a lot like when a record album gets scratched.  Your mind gets stuck in the deep groove created by the trauma and the memory keeps replaying over and over and over again. Your trauma becomes the loudest thing in your mind, overpowering everything else.  Every aspect of life seems different and colored by the potency of your trauma.  

See if any of these sound familiar:

... You can't sleep at night

... Even the slightest reminder of your experience takes you right back to your trauma (a.k.a. 'flashbacks'), making you feel like you are right back there all over again

... You question absolutely everything about your life based on your new reality

... You constantly feel that you are in danger, or that the same thing is going to happen again at any moment

... All conversations seem to lead back to your trauma

... You have trouble working, studying or doing anything that requires focus because your thoughts return to your traumatic event(s)

... You find it impossible to connect with other people who don't understand what you're going through, leaving many relationships on shaky ground

The truth is that most people experience PTSD at some point in their lives. Common causes of PTSD are illness; death of a loved one; unexpected accidents, like a car crash; the destruction of trust (infidelity, etc.); physical or sexual assault; neglect... and of course the big topics that you usually hear about in the news associated with PTSD, such as war, natural disasters, terrorist attacks and other sudden disasters.  Oftentimes, close family members and friends of those who have endured trauma oftentimes end up with PTSD too.

The difference is how people choose to deal with their PTSD.  The 'push it under the rug' technique is a recipe for prolonged suffering and no real resolution.  Healing begins the moment you start to look for help.