Symptoms of post-traumatic stress disorder usually start soon after a traumatic event but may not appear until months or years later. They also may come and go over many years. If the symptoms last longer than four weeks, cause you great distress, or interfere with your work or home life, you might have PTSD.
There are four types of symptoms: reliving the event, avoiding situations that remind you of the event, feeling numb, and feeling extra vigilant about safety. Full story for BostonGlobe.com subscribers.