Who develops PTSD

Post-traumatic stress disorder (PTSD) can start after a frightening, life-threatening event. Most people go through at least one event like this in their lifetime. Yet most of them do not develop PTSD.^2,3

Why do some people get PTSD and others do not? It depends on what happened, your life before it, and the support you had afterward. This page also covers groups at higher risk, such as veterans, refugees, people who survived an intensive care stay, and family caregivers.

What counts as a trauma

Doctors use a specific meaning of "trauma" when they check for PTSD. It means being exposed to death, threatened death, serious injury or sexual violence. This can happen in four ways:⁷

• It happened to you. For example, an assault, a car crash, combat or a disaster.
• You saw it happen to someone else, in person.
• You learned it happened to a close family member or close friend, and it was violent or accidental.
• You faced the details again and again as part of your job. Police officers, paramedics and emergency room staff are examples.

The National Institute of Mental Health lists many kinds of events that can lead to PTSD. These include physical or sexual assault, abuse, accidents, disasters, terror attacks and combat. Ongoing trauma counts too, such as living with an abusive partner.¹

What about the death of a loved one? The sudden natural death of someone close, such as a fatal heart attack, can be a shock. It is one of the most common hard events people face.⁸ But under current U.S. diagnostic rules, a death from natural causes does not count as the starting event for PTSD.⁷ That does not make the pain any smaller. Grief after a sudden loss can be heavy and long-lasting. See our pages on grief and prolonged grief disorder.

How likely is PTSD after a trauma?

A large World Health Organization survey asked nearly 69,000 adults in 24 countries about their lives. About 7 in 10 (70%) had gone through at least one trauma. On average, people had faced about three.⁸

Most people have upsetting memories, poor sleep or feel on edge after a trauma. That is a normal reaction. Most start to feel better within a few weeks.⁵ When strong symptoms last more than a month and get in the way of life, it may be PTSD.⁵

In the United States, about 6 in 100 adults will have PTSD at some point. Women are about twice as likely as men: about 8 in 100 women compared with about 4 in 100 men.³

Symptoms usually start soon after the event. But sometimes they do not show up until months or even years later.⁵ Read more in signs of PTSD.

Some events carry more risk than others

The type of trauma matters a great deal. In the WHO surveys, violence between people carried the highest risk of PTSD.⁸ Rape, other sexual assault and stalking were among the events that caused the most PTSD overall. Sexual violence by a partner stood out as especially harmful.⁸

The unexpected death of a loved one also added a large share of PTSD in that survey. This is mostly because it happens to so many people.⁸ (That survey used a wider definition of trauma than current U.S. rules do.)

Disasters show how closeness to the event matters. In the first year after a disaster:⁶

Risk factors: what raises the chance of PTSD

No single thing causes PTSD. Risk builds from factors before, during and after the event. Many of them are outside a person's control.⁵

Some ways of coping can also raise risk. These include going over the event again and again in your mind, blaming yourself, and avoiding everything that reminds you of it.⁶ Seeing the event as a punishment can do the same.⁶

Trauma early in life matters for later years. People who faced trauma earlier were more likely to face more trauma later. They were also more likely to develop PTSD after it.⁸

Protective factors: what helps people stay well

Researchers call the ability to bounce back "resilience." It comes partly from skills and support that can grow over time.

Things linked with a lower chance of PTSD include:^1,6

• Support from others. Reaching out to friends, family or a support group, and getting help in return. Feeling connected to a caring community.
• Feeling okay about how you acted during the event.
• Having a way to cope and learn from what happened.
• Being able to act during a crisis, even while afraid.
• Hope and a sense that you can cope. Finding meaning through your values or faith.
• Flexible coping. For example, seeing things from a new angle, or taking healthy breaks from hard thoughts.

The VA says social support lowers the chance of PTSD, while stress after the event raises it.⁵ If someone you know just went through a trauma, being there for them matters. See supporting someone with PTSD.

Do genes play a part?

Yes, but only partly. Genes seem to make some people more likely to develop PTSD after a trauma.¹

In 2024, a very large study looked at the genes of about 1.3 million people. It found 95 places in our DNA linked with PTSD.¹⁴ Many of these are tied to stress, fear, threat and the immune system.¹⁴ Each gene has only a tiny effect. There is no gene test that can tell you whether you will get PTSD.

War, military service and refugee trauma

Veterans

Combat is a well-known cause of PTSD.⁵ A large VA study of living veterans found the chance of PTSD differs by the era they served in:⁴

Those numbers do not include veterans who had already died.⁴ Military sexual trauma is another major cause. When screened by VA providers, about 1 in 3 women veterans and 1 in 50 men veterans reported it.⁴

For more about older veterans, and help through the VA, see PTSD in older adults and veterans.

Refugees and people fleeing war

People who flee war often face many traumas, such as violence, loss of family and a dangerous journey. A 2020 review pooled studies of more than 5,000 adult refugees and asylum seekers in 15 countries. It found about 1 in 3 (31%) had PTSD. About the same share had depression.⁹

After a disaster or war, being forced from home and separated from family also raises the risk of anxiety and depression.⁶

Medical trauma: intensive care and heart attacks

Serious illness can be a trauma too.

After a stay in intensive care (ICU)

Survivors of a stay in the intensive care unit (ICU) can have nightmares and unwanted memories. They may have strong reactions to reminders of the hospital. They may also want to avoid thinking or talking about it.¹¹ Doctors call this group of problems post-intensive care syndrome, or PICS. It can also include weakness and memory or thinking problems.¹¹

A 2015 review of about 40 studies looked at PTSD symptoms after an ICU stay. Seven to twelve months later, about 17% to 34% of survivors still had major symptoms. That is roughly 1 in 6 to 1 in 3 people.¹⁰ Risk was higher for people who:¹⁰

• Had frightening or confusing memories from the ICU, such as hallucinations
• Had mental health problems before they got sick
• Received certain calming medicines called benzodiazepines (it is not clear whether the medicine itself raises risk)

Delirium (sudden, severe confusion) in the ICU also raises the chance of PICS.¹¹ See hospital stays and emergency rooms for ways families can help prevent it.

The Society of Critical Care Medicine suggests families keep an ICU diary. Family members write down what happens each day. Later, the patient can read it to make sense of gaps or frightening memories.¹¹ Early research on ICU diaries looks hopeful, but there are not yet enough trials to be sure.¹⁰ Promising

After a heart attack

A heart attack or similar sudden heart problem can also cause trauma symptoms. A review of 24 studies found that about 1 in 8 people (12%) had significant PTSD symptoms afterward.¹² In a few studies, people with those symptoms had about twice the risk of another heart event or death.¹² The research is limited, but tell your doctor if you have fear, nightmares or flashbacks after a heart scare.

Caregiving trauma

Family caregivers can face trauma too. This includes watching a loved one go through a medical emergency, a frightening hospital stay, or sudden violence.

Families of ICU patients. A loved one's critical illness is a crisis for the whole family. Family members can develop their own depression, anxiety and PTSD. About 3 in 10 family members may have mental health problems after a loved one's ICU stay.¹¹ Worry, confusion and making hard choices for someone else all add to the strain.¹¹

Caregivers of people with brain and mental health conditions. A 2024 review looked at 22 studies of family caregivers. They cared for people with dementia and other brain conditions, serious mental illness, or developmental conditions. In some studies, up to half of caregivers reported trauma symptoms. The studies were too different to give one clear number.¹³ Caregivers of people with psychosis named aggression and violence as traumatic events.¹³

If you are a caregiver with nightmares, jumpiness or dread when the phone rings, take these signs seriously. Our page on caregiver stress and burnout has ideas for support. You can also see the caregivers section.

Later life and trauma

Age can work in both directions. Older adults who are in good health often cope well after disasters.⁶ Experience may help. But older adults who are sick, frail, low-income or forced to leave home face higher risk.⁶

Trauma from long ago can also come back later in life. Retirement, the loss of a spouse, illness or memory changes can stir up old memories. Read more in PTSD in older adults and veterans.

Common questions

When to get help

Talk with a doctor or mental health professional if, a month or more after a trauma:⁵

• Upsetting memories, nightmares or flashbacks keep coming back
• You avoid people, places or thoughts that remind you of the event
• You feel on edge, jumpy, numb or cut off from others
• It gets in the way of work, home life or relationships

Only a trained provider can diagnose PTSD.⁵ Learn what to expect in getting assessed for PTSD. Effective help exists. See trauma-focused therapies and coping with trauma symptoms. You can also try our grounding practice for hard moments.

Education only. This page is general information written from the sources listed. It is not medical, legal or financial advice and does not replace a doctor, therapist or lawyer who knows your situation. How we write and check pages.