Posttraumatic Stress Disorder (PTSD) - The Basics

Patient Expert

Posttraumatic Stress Disorder (PTSD) is an anxiety disorder that can occur after you have been through a traumatic event. Strong emotions caused by the event create changes in the brain that may result in PTSD.

When we're in danger, it's natural to feel afraid. This fear triggers many split-second changes in the body to prepare to defend against the danger or to avoid it.

This "fight-or-flight" response is a healthy reaction meant to protect a person from harm. But in PTSD, this reaction is changed or damaged. People who have PTSD may feel stressed or frightened even when they're no longer in danger.

People who have gone through a life-threatening event can develop PTSD. These events can include:

  • Combat or military exposure
  • Child sexual or physical abuse
  • Terrorist attacks
  • Sexual or physical assault
  • Serious accidents, such as a car wreck.
  • Natural disasters, such as a fire, tornado, hurricane, flood, or earthquake.

After the event, you may feel scared, confused, or angry. If these feelings don't go away or they get worse, you may have PTSD. These symptoms may disrupt your life, making it hard to continue with your daily activities.

Most people who go through a traumatic event have some symptoms at the beginning. Yet only some will develop PTSD. It isn't clear why some people develop PTSD and others don't. How likely you are to get PTSD depends on many things. These include:

  • How intense the trauma was or how long it lasted
  • If you lost someone you were close to or were hurt
  • How close you were to the event
  • How strong your reaction was
  • How much you felt in control of events
  • How much help and support you got after the event

Many people who develop PTSD get better at some time. But about 33% of people with PTSD may continue to have some symptoms. Even if symptoms continue, treatment can help. The symptoms don't have to interfere with everyday activities, work, and relationships.

What are the symptoms of PTSD?

Symptoms of posttraumatic stress disorder (PTSD) can be terrifying. They may disrupt life and make it hard to continue with daily activities. It may be hard just to get through the day.

PTSD symptoms usually start soon after the traumatic event, but they may not happen 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 may have PTSD.

There are four types of PTSD symptoms: reliving the event, avoidance, numbing, and hyperarousal.

  1. Reliving the event (also called re-experiencing symptoms): Bad memories of the traumatic event can come back at any time. You may feel the same fear and horror you did when the event took place. You may have nightmares. You even may feel like you're going through the event again. This is called a flashback. Sometimes there is a trigger: a sound or sight that causes you to relive the event. Triggers might include:
    • Hearing a car backfire, which can bring back memories of gunfire and war for a combat veteran (flashback).
    • Seeing a car accident, which can remind a crash survivor of his or her own accident.
    • Seeing a news report of a sexual assault, which may bring back memories of assault for a woman who was raped.
  2. Avoidance of situations that remind people of the event: They may try to avoid situations or people that trigger memories of the traumatic event. They may even avoid talking or thinking about the event. Examples:
    • A person who was in an earthquake may avoid watching television shows or movies in which there are earthquakes.
    • A person who was robbed at gunpoint while ordering at a hamburger drive-in may avoid fast-food restaurants.
    • Some people may keep very busy or avoid seeking help. This keeps them from having to think or talk about the event.
  3. Numbing: People with PTSD may find it hard to express their feelings. This is another way to avoid memories...
    • They may not have positive or loving feelings toward other people and may stay away from relationships.
    • They may not be interested in activities you used to enjoy.
    • They may forget about parts of the traumatic event or not be able to talk about them.
  4. Hyperarousal (feeling keyed up): Those with PTSD may be jittery, or always alert and on the lookout for danger. Hyperarousal symptoms are usually constant, instead of being triggered by things that remind one of the traumatic event. They can make the person feel stressed and angry. Hyperarousal can cause people to:
    • Suddenly become angry or irritable.
    • Have a hard time sleeping.
    • Have trouble concentrating.
    • Fear for their safety and always feel on guard.
    • Be very startled when someone surprises them.

People with PTSD may also have other issues including:

  • Drinking or drug problems
  • Feelings of hopelessness, shame, or despair
  • Employment problems
  • Relationships problems including divorce and violence
  • Physical symptoms

Who develops PTSD?

Anyone can develop PTSD at any age. This includes war veterans and survivors of physical and sexual assault, abuse, accidents, disasters, and many other serious events.

Not everyone with PTSD has personally been through a dangerous event. Some people get PTSD after a friend or family member experiences danger or is harmed. The sudden, unexpected death of a loved one can also cause PTSD. PTSD can also affect children. They may have the symptoms described above or other symptoms depending on how old they are. As children get older their symptoms are more like those of adults. Symptoms children may exhibit include:

  • Young children may become upset if their parents are not close by, have trouble sleeping, or suddenly have trouble with toilet training or going to the bathroom.
  • Children who are in the first few years of elementary school (ages six to nine) may act out the trauma through play, drawings, or stories. They may complain of physical problems or become more irritable or aggressive. They also may develop fears and anxiety that don't seem to be caused by the traumatic event.

Why do people develop PTSD?

It's important to note that not everyone who lives through a dangerous event gets PTSD. In fact, most will not get the disorder.

Many factors play a part in whether a person will get PTSD. Some of these are risk factors that make a person more likely to get PTSD. Other factors, called resilience factors, can help reduce the risk of the disorder. Some of these risk and resilience factors are present before the trauma and others become important during and after a traumatic event. Research is also indicating that genetics are a factor in who develops PTSD.

Risk factors for PTSD include:

  • Living through dangerous events and traumas
  • Having a history of mental illness
  • Getting hurt
  • Seeing people hurt or killed
  • Feeling horror, helplessness, or extreme fear
  • Having little or no social support after the event
  • Dealing with extra stress after the event, such as loss of a loved one, pain and injury, or loss of a job or home.

Resilience factors that may reduce the risk of PTSD include:

  • Seeking out support from other people, such as friends and family
  • Finding a support group after a traumatic event
  • Feeling good about one's own actions in the face of danger
  • Having a coping strategy, or a way of getting through the bad event and learning from it
  • Being able to act and respond effectively despite feeling fear.

Researchers are studying the importance of various risk and resilience factors. With more study, it may be possible someday to predict who is likely to get PTSD and prevent it.


FactSheet. "What is Posttraumatic Stress Disorder (PTSCD)?" National Center for Posttraumatic Stress Disorder.

"What is post-traumatic stress disorder, or PTSD?" National Institute of Mental Health. January 21, 2009.

Gardner, Amanda. HealthDay News. "PTSD Risk Rooted in Stress." The Washington Post. December 9, 2008.