Evidence Based

Acute Stress Disorder vs PTSD: Key Differences, Symptoms & Treatment

Dr. <a href="https://mentalroot.com/author/dr-ethan-myers-md/">Ethan Myers</a>, MD
Written by:
Dr. Ethan Myers, MD
Dr. <a href="https://mentalroot.com/reviewer/dr-emily-foster-pharmd-bcps/">Emily Foster</a>, PharmD, BCPS
Reviewed by:
Dr. Emily Foster, PharmD, BCPS

Updated on: 11.08.2025

read time 10 min read

Highlights Highlights

The fight-or-flight response, also known as an acute stress reaction, is set off by a sudden threat or challenge. It releases adrenaline and usually doesn’t last long.

Acute stress disorder is a severe response to stress that lasts for three to four weeks after a traumatic event.

Post-traumatic stress disorder is a long-term mental illness with symptoms that have been present for more than one month. It is caused by a traumatic event and can last for months or even years.

The main difference between acute stress disorder and post-traumatic stress disorder is the time frame; they are separated by one month. However, many of their causes, risks, symptoms, and treatment options are the same.

I’m sure a lot of people have heard of PTSD, but they don’t really know what it means. In this article, we’ll talk about trauma and stressor-related disorders in more depth, with a focus on two: PTSD and acute stress disorder (ASD).

Trauma can happen to anyone; in fact, a survey by the World Health Organization found that 70% of people around the world would experience one or more traumatic events in their lifetime, with an average of three events per person.

Also, knowing the difference between ASD and PTSD is important for picking the right treatment and putting in place plans to stop the problems before they happen.

Here’s what you need to know before we get into the specifics: both ASD and PTSD begin with an acute stress reaction.

Get assessed for ASD or PTSD symptoms online and receive personalized support from a licensed provider.

Book an appointment

How to Understand the Acute Stress Reaction (ASR) and the Traumatic Stress Reaction

An acute stress reaction, also known as the “fight-or-flight” response, starts as soon as you think or sense that you are in danger. It happens when adrenaline is released, and it only lasts for a short time (<72 hours).

Along with “fight or flight,” other ASR responses are “freeze,” “fright,” “faint,” and “fawn.”

There is another type of stress reaction called a traumatic stress reaction. This is caused by a traumatic event.

Stress and trauma are not the same thing.

When someone goes through something that hurts them physically or emotionally and causes long-lasting mental and emotional distress, along with possible physical, social, or spiritual effects, this is called trauma.

In other words, a traumatic stress response is worse and lasts longer than an acute stress response.

But why do some people get better in hours or days while others fight for months or years? It has to do with something called “fear conditioning,” which means that a normal or everyday thing is linked to the traumatic event and makes people remember how scared they were of it.

Here are two examples to show what I mean:

  1. If someone is in a serious car accident, they might have ASR symptoms every time they drive or hear the song that was playing on the radio at the time of the accident.
  2. If someone was robbed outside of a restaurant after dinner with friends, they might feel in a “fight or flight” state at night or even if they were invited to a get-together that night.

Let’s look at ASD and PTSD in more detail now.

Why do people get Acute Stress Disorder (ASD)?

Acute stress disorder (ASD) is a reaction to a traumatic event that lasts longer than 72 hours but is still pretty short-term. It changes a person’s mood, thoughts, and behavior.

There aren’t any general statistics about ASD after an acute stress reaction, which is a shame. There are, however, some estimates that come after certain traumatic events:

  • Getting into a car accident—13 to 21%
  • 44% had a traumatic injury.
  • Attack—16% to 19%
  • Burns: 10%
  • Being present at a mass shooting—33%

There are five main groups of possible ASD symptoms:

  1. Problems with dissociation. These happen a lot in people with ASD. What does this really mean? Some people might feel like they’re watching their bodies and emotions from the outside, floating around, or like their bodies aren’t real. Also, they might not remember specifics of the trauma because their brains are blocking the memory to keep them safe.
  2. Signs of Arousal. Some of these are trouble sleeping, acting recklessly or hurting yourself, having angry or irritable outbursts, always being aware of danger, having trouble focusing, and having a strong startle response.
  3. Signs of an intrusion. Having repeated, unwanted, and bothersome thoughts; people may have disturbing nightmares or flashbacks, or they may react physically or emotionally when they are reminded of a traumatic event.
  4. Symptoms of Avoidance. By avoiding thoughts and feelings about the event and becoming numb, they stay away from people, places, and things that remind them of the trauma.
  5. Not feeling well. Some people with ASD may find it hard to feel joy, happiness, or hope.

Why do people get Post-Traumatic Stress Disorder (PTSD)?

In the US and Canada, 6 to 9 out of every 100 people will get PTSD at some point in their lives. This is more likely to happen when trauma is planned, violent, or happens more than once than when it happens by accident.

PTSD is a long-term mental illness that lasts more than a month and is caused by a traumatic event that affected the person in some way. This makes them unhappy all the time, changes their thoughts and actions in big ways, and makes it hard for them to do many things in their daily lives. Relationship problems can be caused by problems communicating and feeling detached. Insomnia and anxiety caused by PTSD can make it hard to focus, which can lead to less work or school output or absences. At times, it can be hard to stick to daily routines and enjoy things that used to make you happy.

Acute stress disorder vs ptsd

PTSD and ASD can share some of the same types of symptoms, but the most noticeable signs of PTSD are changes in mood and thought patterns that are not good. People who have PTSD also often:

  • feel bad about themselves and everything around them; 
  • Others and themselves should be blamed for the trauma.
  • no longer have fun in life;
  • Feel guilty, scared, ashamed, and sad all the time;
  • are not able to feel joy, happiness, or contentment anymore;
  • might not remember what happened and feel cut off from other people.

The above-mentioned arousal, intrusion, and avoidance symptoms also happen and look a lot like those in ASD. The dissociative symptoms may also happen, but not as often as in ASD.

Consult an experienced healthcare provider online for PTSD evaluation and personalized support.

Talk to a specialist online

Key Differences Between ASD and PTSD

 

ASD

PTSD

This means

a mental illness that only lasts a short time after a traumatic event

a long-lasting mental illness that happens after a traumatic event

Start

From three days after a hurt

From at least one month after a traumatic event

How long

There are signs for three to four weeks.

Symptoms that last longer than a month; can last for years

In order of how noticeable they are, the symptoms

  • Symptoms of dissociation

  • Not being in touch with yourself (body and emotions)

  • Loss of memory about the trauma

 

  • Symptoms of intrusiveness, avoidance, and arousal

 

  • Not feeling well

  • Not able to feel love, happiness, or success

 

  • Feelings and thoughts that are bad

  • Feeling bad emotions all the time, like fear, guilt, anger, or shame

  • Holding on to false, negative thoughts about oneself or the world

  • Taking too much blame on yourself or others

  • Feeling cut off from other people

  • Loss of interest in things that used to be fun

  • Not being able to feel love, happiness, or satisfaction

 

  • Symptoms of arousal, intrusion, and avoidance 

 

  • Symptoms of dissociation

How to Treat

  • Emotional and practical safety, as well as help from loved ones, first responders, and primary care doctors.

  • Psychotherapy for a short time

  • antidepressants sometimes

  • Psychotherapy for a long time

  • EMDR therapy stands for eye movement desensitization and reprocessing.

  • Some antidepressants are approved by the FDA as treatments.

Results

Nine out of ten people get better.

About half (of them) are better in 3 months.

After two years, one in three people still have symptoms.

Onset and Duration

The main thing that sets ASD apart from PTSD is the time frame: 

  • This is done between three days and one month after the traumatic event. 
  • If symptoms are still there after a month, or for more than a month, it’s likely that the person has PTSD.

PTSD can last for years or months, but ASD only lasts a month or two.

A person can have PTSD years or even decades after the traumatic event. Sometimes this won’t happen until years after the event.

If a person has symptoms of delayed PTSD for at least one month, but no more than six months after the trauma, they may have it.

Most Common Signs

When someone has ASD, dissociative symptoms are more common than negative mood symptoms. When someone has PTSD, the opposite is true.

Treatment

As a result of giving emotional and practical safety and support, it is important to provide “psychological first aid” right after the trauma.

Therapy is the best way to treat both conditions, but for PTSD, sessions need to last for months or even years. Medication has not been shown to help with ASD, but it may be given “off-label” if nothing else works. For example, some antidepressants are approved as a second-line treatment for PTSD.

Prognosis and Outcomes

Most people with ASD will get better with early treatment, but people with ASD are 24 times more likely to die by suicide, be depressed, anxious, or abuse drugs than people without ASD. People who get PTSD will still have symptoms about three out of ten years after they are diagnosed. This makes them more likely to commit suicide and makes it more likely for them to have long-term mental health problems, substance abuse, and job problems.

Call a crisis hotline right away if you’re having suicidal or self-harming thoughts. Some examples are 911, the toll-free 988 suicide & crisis lifeline, or Samaritans (116-123 or chat).

Triggers and Risk Factors for ASD and PTSD

Some examples of potentially traumatic events that could lead to PTSD and maybe even ASD are

  • Assaults on women
  • Acts of violence between people
  • Unnatural events
  • Major accidents
  • The war or terrorism?
  • Long-term neglect of the body or emotions
  • Stress caused by the death or serious illness of a loved one

However, people don’t have to actually go through the event in order to develop ASD or PTSD. Just seeing or hearing about a close family member or friend’s experience can be enough. In some cases, a trigger could be even a vague reminder of a traumatic event that makes you feel bad.

Other people who might be at risk are

  • Friends or family of people who have been traumatized
  • Those who come first, like police, firefighters, and ambulance workers
  • For nurses or doctors
  • Therapists

There are also things that can put a person at risk for getting PTSD or ASD:

  • One or more mental health problems in the past
  • Previous exposure to trauma
  • harm to the body
  • Not getting enough education
  • The female gender
  • Age younger
  • Not doing well financially
  • Not enough help available
  • Longer stays in the hospital or ICU
  • A lot of pain

FAQs

Is it possible to have acute stress disorder and PTSD simultaneously

An ASD consequence is PTSD. A person diagnosed with ASD may still have symptoms that might develop into PTSD in the future. As a consequence, PTSD may develop from acute stress disorder rather than happening simultaneously.

What distinguishes ordinary stress from catastrophic stress?

Stress is a typical physical response to every obstacle in life. As soon as the task is over, it normally goes away and becomes less severe. On the other hand, traumatic stress may be lethal and has a profound effect on an individual’s ability to operate.

What is the timeframe between PTSD and acute stress disorder?

Acute stress disorder lasts for the first few days after a traumatic incident, but post-traumatic stress disorder is a lasting consequence.

Is acute stress disorder reversible?

Indeed! Acute stress problems often resolve on their own. Early diagnosis and therapy prevent it from becoming worse or developing into PTSD.

In this post