Trauma: what it is & how it affects you

Some therapists use the phrase “big T” trauma for events that would shake almost anyone: a car crash, a natural disaster, a violent attack, sexual assault, physical abuse, or war. These often involve a real threat to someone’s life, body or safety.

You can be affected by something that happened to you, something you saw happen, or something you learned happened to someone close to you. Hearing that a loved one was badly hurt can be traumatic too.

The Witnessing a traumatic event guide looks at what it is like to see something terrible happen, and how to cope afterwards.

“Small t” trauma describes experiences that may not make the news but still hurt deeply: being bullied, a painful breakup or divorce, being forced to move, money or legal trouble, or losing a pet. Cleveland Clinic stresses that the “small” is about the type of event, not about how much it affects you.

Ongoing trauma happens again and again, or over a long time, such as living with abuse, neglect, constant conflict or community violence. Because there is no clear “after”, the body may stay on alert for years.

Everyday examples

• A teen who is teased online every day for a whole school year
• A child who never knew if a parent would come home angry
• An adult whose partner slowly chipped away at their confidence
• A family that lost its home and had to start again

Our reaction to an event depends on many things: our age, what else was going on, whether we felt helpless, whether anyone helped us afterwards, and what we had been through before. A doctor at Cleveland Clinic puts it simply: what is traumatic to one person might not faze someone else.

This is why trauma-informed helpers ask “What happened to you?” instead of “What’s wrong with you?” The question moves the focus from blame to understanding.

The VA describes many common reactions after trauma: feeling shocked, numb, scared or sad, trouble sleeping, nightmares, being jumpy, and finding it hard to concentrate. These are normal responses to an abnormal event.

For most people, these reactions slowly fade over the following weeks, especially with safety, rest and caring people around them.

When reactions are very strong, starting from about three days to four weeks after the event, doctors may call it acute stress disorder. It is a short-term reaction that is closely related to PTSD. The main difference is timing.

Getting help early matters, because strong early reactions can sometimes turn into longer-lasting PTSD. The PTSD guide explains the first month in more detail.

PTSD (post-traumatic stress disorder) is when trauma reactions stay, or get stronger, and start to get in the way of work, school, relationships or sleep. NIMH says symptoms usually begin within 3 months of the event, but sometimes they appear later.

PTSD is common and treatable. The PTSD guide covers the signs, who is more at risk, PTSD in children, and the therapies with the strongest research.

Complex PTSD can follow long-lasting trauma, like ongoing abuse in childhood, domestic violence or war. It includes many PTSD experiences, plus deep struggles with emotions, self-worth and relationships.

The World Health Organization’s diagnostic manual (ICD-11) lists complex PTSD, while the main U.S. manual (DSM-5) does not list it separately. The Complex PTSD guide explains more.

The NHS describes dissociation as feeling disconnected from yourself and the world around you. Some people feel as if things aren’t real, or as if they are watching themselves from outside.

It is one of the ways the mind protects itself when things are too much. The Dissociation guide has grounding skills and more support.

The amygdala is like a smoke alarm in your brain. Its job is to notice threats quickly, before you even have time to think. After trauma, it can become “overly aroused”, so it goes off at things that only remind you of danger, like a loud bang, a certain smell, or a raised voice.

The hippocampus, which helps file memories with a time and place, can also be affected. That can make a memory feel like it is happening now, rather than in the past. Some people find they can’t remember parts of what happened for a long time.

In children, ongoing stress (sometimes called toxic stress) can shape how the brain grows, because the brain is still developing. This is one reason childhood trauma can have such long-lasting effects.

The fight response gets you ready to confront danger and push it away. Your muscles tense, your heart pounds, and you may feel hot or shaky.

After trauma, “fight” can show up as snapping at people, arguing, slamming doors, or feeling angry without knowing why. It often comes from a feeling that what happened was unfair, or from a body that still feels under attack.

Flight is the urge to escape. In the moment, it might mean running. Later, it can look like avoiding anything that reminds you of what happened: a road, a type of person, a smell, a conversation, or even your own feelings.

Some people keep constantly busy, so there is never quiet time to feel. Avoidance makes sense in the short term, but over time it can make life smaller and keep fear stuck in place.

Freeze is when your body goes still, sometimes so that you won’t be noticed, or to wait for the danger to pass. You may feel unable to move or speak, or feel far away from your body.

Many survivors blame themselves later: “Why didn’t I do something?” But freezing is an automatic survival response. It happens faster than thought, and it is not something you chose.

Fawn is a newer addition to the list of stress responses. It means trying to stay safe by keeping the threat happy: agreeing, apologizing, going along with things, or putting the other person’s needs first.

Children who grew up with an unpredictable or harmful adult often learn to fawn, because keeping the peace was the safest option. As adults, they may find it very hard to say no, set boundaries, or know what they want.

The “window of tolerance” is an idea first described by psychiatrist Daniel Siegel. It is the zone where your feelings are manageable: you can feel upset and still think clearly, talk, and make choices.

Outside the window

• Above the window (too much): panic, racing heart, anger, feeling flooded or on high alert
• Below the window (too little): numb, frozen, foggy, shut down, far away from yourself

Researchers describe how severe trauma can leave the nervous system easily pushed out of this window by reminders of the past. Some people then reach for risky habits just to feel steady again. The goal of healing is to widen the window, so more of life feels manageable.

Getting back into your window

1. Notice: “Am I too revved up, or too shut down?”
2. If too high: slow your breathing, make your out-breath longer, press your feet into the floor.
3. If too low: move your body, splash cool water on your face, name five things you can see.
4. Remind yourself: “That was then. This is now. I am here.”

A trigger is anything that reminds your brain of the trauma: words, objects, places, sounds, smells, dates, or even a feeling in your body. The alarm goes off as if the danger is back, even when you are safe.

Common kinds of triggers

• Sensory: a smell, a song, a tone of voice, a siren
• Places or situations: a hospital, a crowded room, being alone at night
• Dates: an anniversary or a time of year
• Feelings: being criticized, ignored, trapped or out of control
• Body sensations: a racing heart, being touched in a certain way

Learning your triggers is not about avoiding everything forever. It helps you prepare, understand yourself, and set healthy boundaries. Over time, with support, many triggers lose their power.

During the fight-or-flight response, the body pauses jobs it doesn’t need for instant survival, like digestion and tissue repair, so energy can go to the muscles, heart and lungs. Usually it takes 20 to 30 minutes for the body to calm down again afterwards.

Cleveland Clinic explains that past trauma shapes how we react to threats. For example, someone who was in a car crash may feel the alarm go off when they get in a car, even though that moment is safe.

Living in a state of high alert for a long time, when there is no real threat, can wear down both physical and mental health. Long-term stress can weaken the immune system and add to anxiety and low mood.

Body signs people describe after trauma

• Tense or trembling muscles, as if ready to move at any moment
• Stomach problems, like tummy aches or bathroom changes
• Repeated headaches, or pain anywhere in the body with no clear physical cause
• Trouble falling or staying asleep
• Being easily startled, and always watching for danger
• Feeling disconnected from yourself, your body or the world around you

Children can show it in their bodies too, with lots of tummy aches and headaches, sleep problems, or wetting the bed again after they had stopped.

The PTSD guide goes deeper on sleep, nightmares and pain. For how stress shows up in each part of the body, see the When the body speaks guide.

The NHS describes dissociation as feeling disconnected from yourself and the world around you. Some people feel dazed, as if things aren’t real, or as if they are watching themselves from outside.

Numbness turns the volume down when feelings are too much. It made sense at the time. As you feel safer, feeling can slowly return.

A gentle way back in (go slowly)

1. Start at the edges: notice your feet on the floor or your hands on your lap.
2. Pick one neutral sensation, like the temperature of your hands or the texture of your sleeve.
3. Keep your eyes open and look around the room if that feels safer.
4. Stop whenever you want. Noticing for ten seconds counts.

The original CDC-Kaiser Permanente ACE Study ran from 1995 to 1997. Over 17,000 adults in Southern California had a physical exam and filled in a private survey about their childhood and their health. The CDC calls it one of the largest studies of its kind.

Almost two in three people reported at least one adverse childhood experience (ACE), and more than one in five reported three or more. The study found what scientists call a “dose-response” link: as the number of ACEs went up, so did the risk of poorer health and wellbeing later in life.

Today the CDC says ACEs can raise the risk of long-term diseases such as heart disease, diabetes and cancer. Toxic stress in childhood can affect brain development, the immune system and the body’s stress-response systems.

In 2025, psychiatrist Michael Scheeringa published a review of 122 claims from the book in the journal BJPsych Bulletin. He concluded that its key claims, that trauma damages the brain and that body-based treatments work uniquely well, are not supported by the current weight of research.

One example is brain scans. They do show differences between people with and without PTSD. But most studies are snapshots in time. Studies that measured people before a trauma suggest that some differences may have been there beforehand, and may make some people more vulnerable.

In a 2026 opinion article, a group of neuroscientists argued that the body does not literally store trauma. In their view, the brain keeps predicting danger, and the body joins in as a messenger rather than an archive. They agree that body states matter in trauma and that it is not “just in your head”.

People-pleasing is often seen as just being kind. But for some people, it is a survival strategy learned when keeping others happy was the safest option.

It might look like

• Apologizing for everything
• Not knowing your own opinion or needs
• Feeling panicky when someone is upset with you
• Saying yes when you are exhausted

After trauma, some people feel shocked, numb, or unable to feel love or joy. They may pull away from others. This is a way the mind turns down the volume on feelings that were too much.

Others may read numbness as coldness or not caring. In fact, it often protects someone who cares a lot and was hurt deeply.

Anger is a common reaction after trauma, often linked to a sense that what happened was unfair. It can also come from feeling constantly on edge.

Anger itself is a normal feeling. But violent reactions make things worse and can lead to harm. Learning to spot early signs, like a tight jaw or hot face, helps you step away in time.

When a trigger hits, the body responds to the past danger, not just the present moment. So a slammed door, a raised voice, or being ignored can bring a reaction that seems “too big” to others.

Some people can’t remember parts of a traumatic event, sometimes for many years. Others feel detached from themselves or the world around them, as if they are watching from outside.

This is the “below the window” state: the mind shutting down to cope. Grounding helps bring you back to the here and now. The Dissociation guide explains more.

Some people use alcohol, substances, food, overworking, or risky behaviour to escape painful feelings or memories. These are often attempts to calm a nervous system that won’t settle.

The WHO advises cutting down on alcohol and substances after trauma, because they can make symptoms worse. Kinder ways to cope can be learned, and support is available without judgment.

Being very ill, waking up in intensive care, or going through scary procedures can leave lasting fear. The NHS lists serious illness needing intensive care, a difficult birth, and the death of a baby among causes of PTSD.

Intensive care survivors may have confusing or frightening memories of their stay. In a 2007 review of 16 studies of medical ICU patients, rates of PTSD or PTSD symptoms ranged widely, from 5% to 63%. The authors cautioned that the higher numbers may be overestimates, but it is clearly not rare.

Birth trauma can follow a long or painful labour, an unplanned caesarean, emergency treatment, or feeling unsupported or unheard. NHS Scotland notes that birth partners can be traumatised too. Signs include reliving the birth, feeling on edge, avoiding reminders, and blaming yourself. The Hard or frightening births guide goes deeper.

What can help

• Ask your care team to go over what happened, so the memory makes more sense
• Tell your doctor or health visitor how you’ve been feeling since
• Bring a trusted person to future appointments
• Ask about trauma-focused therapy if feelings last more than a few months

For many people, faith and religious community are a huge source of comfort, meaning and belonging. Religious trauma is not about faith itself. It can happen when a group or leader a person trusted became controlling, manipulative, shaming or abusive.

People may carry deep fear of punishment, shame, confusion about what to believe, or find it hard to trust others or join a new community. Some keep their faith and heal within it. Others step away. Both paths deserve respect.

Being in an abusive, controlling or manipulative relationship can leave lasting harm, including gaslighting, where someone makes you doubt your own memory or judgment. It can deeply affect self-worth and trust.

Afterwards, some people pull away from others, while others move quickly into new relationships. Both can be ways of coping with the hurt.

Sexual trauma includes assault and other harmful sexual experiences where there was no informed consent. It can happen in childhood or adulthood, by strangers or by people known and trusted. The Sexual assault & rape guide and the Childhood sexual abuse guide offer more support.

Survivors may avoid medical exams, struggle with closeness, or feel shame that does not belong to them. The VA notes that women are more likely than men to experience sexual assault, but people of every gender are affected.

Disaster mental health workers use a model of “phases” to describe how communities often feel over time. SAMHSA describes it like this: feelings get harder around the warning and the impact. Then comes a heroic phase, when people rush to help, and a honeymoon phase, when the community feels close and united.

After the honeymoon often comes disillusionment, sometimes because recovery is slower than people hoped. SAMHSA notes it typically arrives in the second half of the year after the disaster. After the first anniversary, it is generally followed by reconstruction, as people come to terms with a “new normal”.

What this can look like in real life

• Week 1: neighbors pulling each other out of flood water, strangers dropping off food
• Month 2: fundraisers, community meals, a strong sense of “we’re in this together”
• Month 8: insurance still not paid, people exhausted, tempers short, volunteers gone
• Year 2: new routines, rebuilt spaces, memorials, and a changed but steadier community

After the 2013 Boston Marathon bombings, researchers surveyed thousands of people across the U.S. They found that people who took in six or more hours a day of bombing-related media in the week afterwards reported more acute stress than people who were actually at the scene.

This does not mean news is bad. Knowing what is happening can keep you safe. But graphic images and endless replays can keep the body’s alarm switched on, as if the danger is still happening to you.

Ways to stay informed without flooding yourself

• Pick one or two trusted sources and check them at set times
• Read updates instead of watching videos when you can
• Turn off auto-play and graphic content settings
• Keep news out of the bedroom and the last hour before sleep
• Notice when you’re scrolling to feel safer, but feel worse instead

A SAMHSA research bulletin describes how, after Hurricane Katrina, some mental health problems became more common in the year after the first survey, not less. The researchers linked this to stressors like housing and money problems that were still going on nearly two years after the storm.

In other words, recovery is not only about the memory of the event. It is also about whether people get their lives back: a home, school, work, and a sense of control.

SAMHSA’s Disaster Distress Helpline is open to survivors, loved ones of victims, first responders, rescue and relief workers, clergy, and parents and caregivers. That list is a good reminder of how widely a disaster can reach.

People who share an identity with those who were targeted, such as the same faith, race, school or community, may feel the pain closely even from far away. For more on racism and discrimination as a source of stress, see the Culture & mental health guide.

Rescue workers, nurses, police, firefighters and journalists can carry heavy stress from what they see. The First responders and Healthcare workers guides cover secondary trauma and support for people in these roles.

The Disaster Distress Helpline is run by SAMHSA. It is free, open 24 hours a day all year, and for anyone in the U.S. and its territories who is struggling emotionally after a natural or human-caused disaster. You can call for yourself or someone else.

It covers events like

• Hurricanes, tornadoes, floods, wildfires, earthquakes, drought and extreme heat
• Incidents of mass violence
• Infectious disease outbreaks, like the COVID-19 pandemic
• Incidents of community unrest
• Anniversaries and other trigger events

Good to know

• Call or text 1-800-985-5990
• For Spanish, call or text the same number and press 2
• Interpreters are available in over 100 languages
• Deaf and hard of hearing callers can use their preferred relay service
• You don’t have to give your name

Communities often find their own ways to heal: vigils, prayer services, memorial walls, rebuilding days, art projects and anniversary events. These give people a place to put their grief and a reminder that they are not alone. The VA notes that, alongside the pain, shared disasters can bring people together and help build resilience.

Ways you can help

• Check on older neighbors, people living alone, and families with young kids
• Offer specific help: “Can I bring dinner Thursday?” rather than “Let me know if you need anything”
• Share the Disaster Distress Helpline number in your group chats, faith community or workplace
• Keep showing up in the months after, when attention fades but needs remain
• Respect that people grieve differently. Some want to talk; some want to work quietly

Some anniversaries are public, like the date of a terror attack or a disaster, with memorials and news coverage every year. Others are private: the day a loved one died, the date of an assault, or the day of a car crash.

Holidays can carry weight too. The VA gives the example of Memorial Day for someone who lost a friend in service. A season can be a reminder as well: after a hurricane, even rain at that time of year can feel threatening.

Other dates people mention

• A birthday of someone who died
• The first day of school, if something happened at school
• A court date or the day someone was released
• The time of year a family was forced to leave home
• Family holidays that used to be tense or unsafe

Common anniversary reactions

• Intense memories, or the body reacting as if it is happening again
• Avoiding people, places or events linked to what happened
• Sadness, guilt or shame coming back
• Finding it harder to feel close to people
• Feeling jumpy, irritable, or unable to sleep or focus
• Worry, panic, tiredness, aches or grief

Dread can be part of it too. Some people feel anxious for weeks before the date, worrying about how hard it will be. And when the event was public, news stories and social media posts can make the reminders hard to escape.

Not everyone has an anniversary reaction, and they don’t all look the same. A reaction does not mean you are going backwards.

The VA suggests making plans for the day, rather than waiting to see how you feel. Choose things that give you a break, or that give the day meaning.

Ideas from the VA and others

• Visit a grave or a meaningful place
• Donate to a cause, give blood, or help someone else
• Spend the day with family or friends who understand
• Plan something restful or enjoyable you can look forward to
• Take a break from news and social media if the event was public
• Protect your basics: sleep, food, movement and breathing exercises

Tell the people close to you what kind of support you want. “Can you text me that morning?” or “I’d like company but not questions” makes it easier for them to help.

The VA points out that anniversaries can also be a chance for growth: a time to honor someone, to remember, or to mark how far you’ve come since the worst day.

Rituals people create

• Lighting a candle or saying a prayer
• Cooking a loved one’s favourite meal
• Writing a letter to yourself, or to the person you lost
• Walking a route that feels peaceful
• Gathering with others who were there

According to the VA, most people feel better within a week or two after the anniversary, and the distress generally becomes less frequent and less intense as time goes on.

After a community disaster, SAMHSA notes that people may hit an emotional low around the one-year mark before moving into a slower phase of rebuilding.

If anniversaries still bring a lot of distress year after year, that is a good reason to talk with a therapist. The VA notes that effective treatments exist, even if you didn’t get help right after the event.

The VA says that emotional reactions to trauma are common and are not a sign of weakness. Trauma affects the body’s survival systems, which work the same way in everyone.

Unresolved trauma can affect the present. Childhood experiences can shape adult health, and reactions can appear long after the event.

The good news: it is never too late to start healing.

Around 70% of people worldwide go through a potentially traumatic event, but only a minority develop PTSD. Having support from others afterwards is one of the things linked to lower risk.

Good trauma therapy builds a safe, trusting relationship first. You can set boundaries around topics and words. Some therapies involve talking about memories, and some focus more on thoughts or the body.

Effective talk therapies exist, and most last about three months. Up to 40% of people with PTSD recover within a year, and many more improve with treatment.