What Is Trauma?

The word trauma gets used for a car crash, a hard childhood and a rough week at work. It can be hard to tell whether it applies to what happened to you.

This article sets out what official sources mean by a traumatic event and by trauma, how common such events are, the range of reactions that can follow, and why most people who live through one do not develop post-traumatic stress disorder (PTSD). It describes. It does not diagnose, and it will not ask you to go back over anything. Only a clinician can assess what you are dealing with.

What do clinicians mean by a traumatic event?

They mean an event that is shocking, frightening or dangerous. The National Institute of Mental Health (NIMH) puts it this way: "A traumatic event is a shocking, scary, or dangerous experience that can affect someone emotionally and physically." Its examples include natural disasters, acts of violence, and car crashes or other accidents.

The VA's National Center for PTSD separates stress from trauma. It says "not all stressful events are the type of trauma that can lead to PTSD," and that to be at risk for PTSD, "the trauma must be a shocking and dangerous event that you see or that happens to you."

Is the everyday meaning of trauma wider than the clinical one?

Yes. The American Psychological Association's Dictionary of Psychology defines trauma broadly, as "any disturbing experience that results in significant fear, helplessness, dissociation, confusion, or other disruptive feelings intense enough to have a long-lasting negative effect on a person's attitudes, behavior, and other aspects of functioning." That definition turns on the effect on the person.

The definition used for a PTSD diagnosis is narrower. As the 2023 VA/DoD clinical practice guideline describes the American diagnostic manual, DSM-5-TR, an event can meet it in any one of four ways:

• Direct exposure to an event involving actual or threatened death, serious injury or sexual violence.
• Witnessing such an event, including when the person watching is unharmed.
• Learning that a loved one was exposed to or died during a traumatic event. A death meets the definition only if it was violent or accidental.
• Repeated exposure to details of trauma as part of professional duties. The guideline's examples include medical, law enforcement and journalism personnel.

So the word has two senses. Under the broad one, an experience that falls outside the narrow definition can still count as trauma because of its lasting effect on the person.

How common are traumatic events?

Very common. The VA says: "Most of us will experience at least one trauma in our lifetime that could lead to PTSD." It gives no percentage.

One study, by Kilpatrick and colleagues in 2013, surveyed a national sample of 2,953 U.S. adults recruited from an online panel. Using DSM-5 criteria, 89.7% reported exposure to a traumatic event, and exposure to more than one type of event was the norm. The limits matter: it was a self-administered online survey with no clinical interview.

Worldwide, the World Health Organization (WHO) says around 70% of people will experience a potentially traumatic event during their lifetime. That is a global figure, not a U.S. one.

What reactions are common after a traumatic event?

Strong ones, in the body and in the mind. The VA's list of common reactions includes:

• Dreams and memories that upset you.
• Feeling jumpy, on guard and alert.
• Trouble sleeping, feeling very tired and being unable to concentrate.
• Feeling nervous, helpless, fearful or sad.
• Feeling shocked or numb.
• Avoiding people, places and things related to the event.

The VA says of these: "Such stress reactions are normal and not weakness. Most people recover in time." What the first weeks tend to look like is covered in after a traumatic event, and the physical side in how trauma affects the body.

Does a traumatic event always lead to PTSD?

No. The VA states: "Most people who go through a traumatic event will not develop PTSD." Its best estimates are that about 6 of every 100 people in the U.S. will have PTSD at some point in their lives, and that about 5 of every 100 adults have it in any given year. A VA page written for providers reports the same lifetime and past-year figures from a national survey of more than 36,000 U.S. adults carried out in 2012 and 2013 using DSM-5 criteria. The VA adds that the exact number of people who have PTSD is not known.

The WHO's global estimate is that only a minority, 5.6%, of people who experience a potentially traumatic event go on to develop PTSD.

Several things affect who does. The VA says: "Anyone can develop PTSD at any age." It says very intense or long-lasting trauma makes PTSD more likely, and that what happens afterward is also important: "Stress can make PTSD more likely, while social support can make it less likely."

PTSD symptoms explains what clinicians look for. Complex PTSD covers a related diagnosis.

When is it worth talking to a professional?

The VA gives three signs. It says to talk to a doctor or mental health care provider if your symptoms last longer than a month, are very upsetting, or disrupt your daily life. It also says: "Only a mental health provider can diagnose PTSD."

If you are thinking about harming yourself, call or text 988, or call 911 in an emergency.

Whether therapy is the right step is a separate question. Do I need trauma therapy? takes it up.

What kinds of help exist?

For PTSD, U.S. guidelines most strongly recommend specific trauma-focused psychotherapies. The 2023 VA/DoD guideline names cognitive processing therapy, EMDR and prolonged exposure. The American Psychological Association's 2025 guideline names cognitive processing therapy, prolonged exposure and trauma-focused cognitive behavioral therapy. Both found insufficient evidence to recommend for or against psychodynamic therapy, which has been studied much less for PTSD. Types of trauma therapy goes through the research.

Dr. Rabin is a licensed clinical psychologist who offers trauma therapy in Brookline and by telehealth across Massachusetts. Her approach is psychodynamic, attachment-based, trauma-informed and mindfulness-based, guided by safety, pacing and the therapeutic relationship. The work moves at the client's pace, and the client decides what is discussed and when.

You can request a free consultation of about 15 minutes through the contact page. It is a reasonable place to ask whether she offers a particular treatment or would refer you to someone who does.

Keep reading

• PTSD Symptoms: What Clinicians Look For
• Do I Need Trauma Therapy?
• Types of Trauma Therapy and What the Research Says
• All trauma guides

Sources

• National Institute of Mental Health, Coping With Traumatic Events (last reviewed May 2024)
• VA National Center for PTSD, How Common is PTSD in Adults? (last updated September 25, 2026)
• VA National Center for PTSD, PTSD Basics (page header: Last Updated October 2026)
• American Psychological Association, APA Dictionary of Psychology: trauma (updated 2018)
• U.S. Department of Veterans Affairs and Department of Defense, VA/DoD Clinical Practice Guideline for Management of Posttraumatic Stress Disorder and Acute Stress Disorder (June 2023)
• Kilpatrick DG, Resnick HS, Milanak ME et al., National estimates of exposure to traumatic events and PTSD prevalence using DSM-IV and DSM-5 criteria. J Trauma Stress (2013)
• World Health Organization, Post-traumatic stress disorder fact sheet (11 September 2026)
• VA National Center for PTSD, Epidemiology and Impact of PTSD (last updated August 20, 2026)
• VA National Center for PTSD, Common Reactions After Trauma (last updated September 25, 2026)
• American Psychological Association, Clinical Practice Guideline for the Treatment of Posttraumatic Stress Disorder (PTSD) in Adults (2025)

Last reviewed October 2026. This guide is general information, not medical advice or a diagnosis. If you are in crisis or thinking about harming yourself, call or text 988, or call 911 in an emergency.