Post-traumatic stress disorder (PTSD) is an anxiety disorder caused by very stressful, frightening or distressing events.
Someone with PTSD often relives the traumatic event through nightmares and flashbacks, and may experience feelings of isolation, irritability and guilt.
They may also have problems sleeping, such as insomnia, and find concentrating difficult.
These symptoms are often severe and persistent enough to have a significant impact on the person’s day-to-day life.
Read more about the symptoms of PTSD.
The type of events that can cause PTSD include:
PTSD can develop immediately after someone experiences a disturbing event or it can occur weeks, months or even years later.
PTSD is estimated to affect about 1 in every 3 people who have a traumatic experience, but it's not clear exactly why some people develop the condition and others don't.
Read more about the causes of PTSD.
People who repeatedly experience traumatic situations such as severe neglect, abuse or violence may be diagnosed with complex PTSD.
Complex PTSD can cause similar symptoms to PTSD and may not develop until years after the event. It's often more severe if the trauma was experienced early in life as this can affect a child's development.
Read more about complex PTSD.
It's normal to experience upsetting and confusing thoughts after a traumatic event, but most people improve naturally over a few weeks.
You should visit your GP if you or your child are still having problems about four weeks after the traumatic experience, or if the symptoms are particularly troublesome.
If necessary, your GP can refer you to mental health specialists for further assessment and treatment.
PTSD can be successfully treated, even when it develops many years after a traumatic event.
Any treatment depends on the severity of symptoms and how soon they occur after the traumatic event. Any of the following treatment options may be recommended:
Read more about treating PTSD.