Types of PTSD: What Causes Post-Traumatic Stress Disorder?

Reviewed By: Brian Pilecki, Ph.D.

There are different types of PTSD, just as there are different causes. It’s normal to have unique responses to traumatic events. Some people can bounce back from a stressful event relatively quickly. Others have a more challenging time. They might deal with lingering symptoms like flashbacks, depression, and irritability for months or years after their initial trauma.

We don’t fully understand why some people get PTSD while others don’t, but we do know that it is not someone’s fault if they do struggle with traumatic events. If you think you have PTSD, you’re not alone. About 6 out of 100 people (or 6% of the population) will have PTSD at some point in their lives. 1

Learning about the different types of PTSD can give people the language they need to recognize what they’re feeling. So, let’s talk about how PTSD can appear in your life.

If you’re experiencing a mental health crisis and need help now, call 911 or the National Suicide Prevention Lifeline (1-800-273-8255).

What is Post-Traumatic Stress Disorder (PTSD)?

Post-traumatic stress disorder (PTSD) is a condition that can occur in people who experience traumatic events. Many different events can cause PTSD, like a life-threatening accident, a natural disaster, sexual violence, or war. 2

PTSD was previously called “shell shock” and “combat fatigue.” These terms described combat veterans’ symptoms after World War I and World War II. However, anyone can get PTSD, not just combat veterans.

PTSD can co-occur with other conditions, such as substance abuse, mood and anxiety disorders, or self-harming behaviors. 3 PTSD is also associated with health disorders like chronic pain, heart problems, and even a heightened risk of dementia. 2

What Are the Different Types of PTSD Symptoms?

PTSD symptoms can vary widely. We’ve listed a few common ones below, but it’s important to remember that this disorder can affect people differently. 4 You might have all or some of these symptoms. (Confusing, we know.)

Intrusive thoughts
Nightmares
Flashbacks of the traumatic event
Guilt or self-blame
Irritability
Hypervigilance
Difficulty sleeping
Poor concentration
Emotional withdrawal
Avoiding people, places, or situations that might trigger distressing memories
Self-destructive behaviors
Difficulty trusting others

Symptoms might start within a month of the traumatic event, but some people don’t experience anything until years later. 5

For a person to be diagnosed with PTSD, their symptoms must last for more than a month and significantly disrupt their daily life.

What is Hypervigilance, and How Does It Relate to PTSD?

Hypervigilance means a person is on high alert for a potential threat. They’re anxious, tense, and constantly on guard.

Humans evolved with a natural defense system. If your body senses a threat, your brain sends signals: your heart rate increases, your muscles tense, and your body prepares to defend itself. It’s exhausting to stay in that state forever, so your body has systems to bring you back to baseline and calm down your defenses.

Hypervigilance is like being caught in a perpetual fight-or-flight response. It can cause people to misinterpret ambiguous situations, exaggerate minor threats, and fall into feedback loops of anxiety. 6

This symptom is closely related to anxiety disorders like PTSD. Traumatic events can cause changes in the brain that alter a person’s automatic responses to danger, causing them to stay hypervigilant.

Oh, and those causes of danger? They might be real or imagined. Unfortunately, the hypervigilant brain doesn’t know the difference. The hypervigilant brain feels like it is better to be safe than sorry, even if that means sacrificing a person’s well-being.

Traumatic events increase stress hormone levels and change the brain’s threat response. 7 ,8 They also compromise the brain area that “communicates the physical, embodied feeling of being alive,” writes Bessel van der Kolk, MD, in his book The Body Keeps the Score. “These changes explain why traumatized individuals become hypervigilant to threat at the expense of spontaneously engaging in their day-to-day lives.” 9

What’s it Like to Have PTSD?

PTSD affects people differently. It might feel like they’re always on edge, waiting for a danger that never comes. They might avoid being in large crowds, hugging people, and other situations that remind them of their trauma.

People living with PTSD may relive their experience through flashbacks or nightmares. (On a related note, difficulty sleeping is a common symptom of PTSD). In addition, they might have mood swings, a sense of detachment or hopelessness, and withdrawal from others.

They might also have strong reactions to seemingly unrelated things, like the sound of a slamming door or raised voices.

What Is the Difference Between PTS and PTSD?

Post-traumatic stress (PTS) is a normal stress response. Treatment usually isn’t necessary with PTS, as symptoms subside after the stressor is removed. PTSD is a disorder that occurs when stress response symptoms persist for at least one month. While PTS is temporary, PTSD symptoms can endure for years or a lifetime, and they tend to disrupt a person’s daily life.

After a normal stressful event, self-care practices like exercise, journaling, and meditation can help people feel better (basically, whatever you usually do to unwind). If the stressful events were particularly intense, a person’s symptoms stick around longer than one month, and their usual relaxation techniques aren’t cutting it, they may have developed PTSD.

PTS describes the body’s natural response to a traumatic event, like a car accident or a breakup. Your fight-or-flight response kicks in: Your brain tells your body to breathe faster, pump more blood, and tense your muscles.

Think of PTS this way: How does your body feel when you get into an argument? Your heart races, your muscles tense up, and you feel flushed. You might avoid that person for a period afterward, but ultimately, you move on with your life.

It is important to understand that PTSD is not due to a person being weak or failing in some way. Rather, PTSD is a complex condition that happens to people, even people who are strong, smart, and adaptive.

Ultimately, it’s important to recognize that PTSD a built-in mechanism that is there to protect you. It develops after your defenses have been activated. The difficulty comes in when the body conintually reacts to non-threatening situations as if they were threats.

Who is at Risk of Developing PTSD?

PTSD can happen to anyone, but studies indicate that certain groups of people are more likely to develop PTSD. 2

People who work with severely ill patients
Journalists and their families
Victims of war
Rescue workers
Members of the armed forces
High-risk children who experienced abuse, natural disasters, or the loss of a parent

In a study of rescue workers after 9/11, researchers found that people who were least likely to have had prior disaster training or experience were at the most significant risk of PTSD. 10 That group included construction or engineering workers, sanitation workers, and unaffiliated volunteers.

Jobs that involve chronic exposure to harmful content may also be associated with anxiety disorders, such as a form of PTSD called vicarious trauma. 11 That term refers to people negatively affected by a traumatic event, even if it doesn’t directly happen to them. 12

This is concerning for platforms like Facebook and Reddit, where content moderators review violent and extremist content daily.

What are the risk factors for PTSD?

A risk factor increases a person’s likelihood of developing a health condition. The following risk factors might make a person more likely to develop PTSD:2,13

Duration and intensity of the trauma
History of previous traumatic experiences
History of abuse
Family history of PTSD or depression
Substance abuse
Lack of social support
Poor coping skills
Chronic stress
Gender (the prevalence of PTSD is almost twice as high in women as it is in men)
Lower levels of education and income
Being divorced or widowed
History of behavioral or mental disorder

So, why do some people develop PTSD and other people do not? We don’t know for sure. Two people can experience the same traumatic event and react radically differently.

Types of trauma

There are different reactions to traumatic events, and there are also various types of trauma that can lead to the development of PTSD:

Type 1 trauma: A reaction to a single, discrete traumatic event (like sexual assault, a significant accident, or a natural disaster)
Type 2 trauma: A reaction to traumatic material over some time (like a history of abuse)

Most people associate PTSD with type 1 trauma, and type 1 is most commonly studied. However, type 2 trauma (also called TTT) can also lead to PTSD. TTT frequently occurs among people who work with children who are victims of trauma. 14

Types of PTSD

PTSD is complicated. Some people are constantly on alert, and others feel mentally checked out. Depending on a person’s symptoms, they may be diagnosed with a subtype of PTSD like:

Comorbid PTSD
Complex PTSD
Dissociative PTSD
Uncomplicated PTSD

Complex PTSD

Complex PTSD (or CPSTD) is a more severe form of PTSD. It’s associated with major traumatic events like totalitarian control over a prolonged period, such as prisoners of war, survivors of domestic violence, and childhood sexual abuse. 15

This subtype has five common features:16

Emotional flashbacks
Toxic shame
Self-abandonment
Vicious inner criticism
Social anxiety

In his book Complex PTSD: From Surviving to Thriving, psychotherapist Pete Walker notes that emotional flashbacks are perhaps the most noticeable and characteristic feature of CPTSD. Emotional flashbacks are sudden, prolonged regressions to feelings like fear, shame, rage, and grief, which Walker describes as the “feeling-states of being an abused/abandoned child.”

Among other characteristics, a person with complex PTSD might have intense fluctuations in mood, occasional episodes of dissociation, and difficulty relating to others. They might also have a preoccupation with the perpetrator, like feeling obsessed with the idea of revenge.

Comorbid PTSD

This subtype is the opposite of uncomplicated PTSD. “Comorbid” refers to conditions that co-occur in a patient. The following conditions are associated with PTSD: 17

Anxiety disorders like generalized anxiety and panic disorders
Mood disorders like depression and bipolar disorder
Nicotine dependence
Social and specific phobias
Substance abuse
Suicidality

Traumatic events can trigger PTSD and comorbid disorders, but there’s no guarantee that people will develop more than one disorder. Researchers speculate that comorbid PSTD might depend on factors like a person’s genetics and the extent of their trauma. 17,18

Dissociative PTSD

“Dissociation” means feeling disconnected or separated from something else. A person with dissociative PTSD feels like the world isn’t real (derealization) or like they aren’t real (depersonalization). 19,20

Dissociation also occurs on a spectrum, from mild “checking out” or “disconnecting” to more severe bouts where a person may lose contact with reality, have a flashback, or not remember periods of time.

Other subtypes of PTSD are associated with feeling alert, on edge, and ready to run. Dissociative PTSD is different. It causes people to feel numb and disconnected after being exposed to trauma.

Both responses are adaptive when trauma occurs. The brain’s ability to dissociate protects us from experiencing the fullness of the pain, and the fight-or-flight response mobilizes us to act. The problem is that once the brain learns these coping mechanisms, it over-relies on them—even long after the trauma has ended.

This reaction happens on the biological level, too. Researchers have found that people with dissociative PTSD don’t have the same fight-or-flight response; where others will experience an increase in heart rate, the person with dissociative PTSD will not. 21

Potential risk factors for dissociative PTSD include:

Development of PTSD in childhood
Re-experiencing symptoms, particularly among men
History of separation anxiety disorder and specific phobias
History of trauma
Suicidality

Uncomplicated PTSD

This subtype is “uncomplicated” because it isn’t associated with other behavioral or mood disorders. For example, a person with PTSD can also have depression or anxiety disorder, but a person with uncomplicated PTSD solely has PTSD. (That doesn’t mean it’s any easier, though.)

Uncomplicated PTSD shares symptoms with other subtypes, like reliving a traumatic event, avoiding potential triggers, and a sense of hypervigilance.

And like other subtypes, people with uncomplicated PTSD may respond to group, psychodynamic, cognitive behavioral, pharmacological, or combination therapies. 22

Is acute stress disorder a form of PSTD?

Acute stress disorder (ASD) gets lumped into PTSD, but it’s not the same.

Like PTSD, ASD can occur in people who have experienced a traumatic event. The difference is that their symptoms resolve within the first month.

Said another way, the symptoms of ASD are a lot like PTSD symptoms: a person might feel anxious and helpless, dissociate, relive the event, and avoid potential triggers. If the symptoms stick around after one month, the person may have developed PTSD.

People with ASD are at a higher risk of developing PTSD. The following risk factors can place you at a higher risk of developing ASD after a traumatic event:

History of PTSD
History of mental health disorder
Prior exposure to trauma
Tendency to dissociate in response to trauma

It’s important to note that not everyone who experiences ASD will develop PTSD. According to the U.S. Department of Veterans Affairs, cognitive behavioral therapy (CBT) is an effective treatment for people with ASD. 23

PTSD Frequently Asked Questions

What is post-traumatic stress disorder (PTSD)?

PTSD is an anxiety disorder. It develops in response to traumatic events, like a life-threatening accident, assault, and domestic violence. PTSD can affect people differently, and not everyone who endures a traumatic experience will develop PTSD.

Who is more likely to develop PTSD?

Combat veterans
Families of people in high-risk jobs
High-risk children who have been abused or experienced a traumatic event
Journalists
People who work with severely ill or traumatized children or adults
Rescue workers
Victims of war
Anyone who is exposed to trauma regularly, such as content moderators or emergency dispatchers

What are the types of PTSD?

Comorbid PTSD
Complex PTSD
Dissociative PSTD
Uncomplicated PTSD

Is acute stress disorder a type of PTSD?

No. Acute stress disorder (ASD) has similar symptoms as PTSD, like anxiety, flashbacks, and avoidance. However, ASD refers to symptoms within four weeks after the traumatic event. If symptoms stick around longer than a month, it’s considered PTSD.

What will PTSD do to a person?

PTSD makes a person feel stressed and frightened, even when they’re safe. These feelings can cause a person to experience flashbacks, avoid certain situations that remind them of their trauma, and use with alcohol or drugs to cope, among other reactions.

There are many different ways that PTSD can impact a person’s life. They might experience:

Anxiety
Avoidance
Depression
Emotional outbursts
Insomnia
Memory problems
Nightmares and flashbacks
Self-isolation
Substance abuse issues
Difficulty in relationships

What are PTSD examples?

Certain people, events, and situations may remind a person of their trauma, and those PTSD triggers are different for everyone. Examples of PTSD triggers include:

Being touched in a certain way
Encountering people related to the trauma or who share physical characteristics
Feeling anxious or panicked
Hearing or reading certain words or descriptions
Locations that remind a person of the trauma
Loud sounds
Objects, such as a knife or gun
Reminders of certain dates
Specific scents and tastes

Does PTSD go away?

PTSD can be treated. With proper medical treatment and coping strategies, many PTSD sufferers can process their trauma and live fulfilling lives. Treatment options include cognitive-behavioral therapy, eye movement desensitization and processing (EMDR), and exposure therapy, among others.

The Bottom Line

There isn’t a one-size-fits-all definition of PTSD. It can affect people differently, depending on the extent of trauma, its duration, and a history of trauma in a person’s past (among other factors).

If you’re struggling with symptoms after a traumatic experience, you have options. Talk therapy can help people cope with their symptoms, learn how to process their trauma, and manage potential triggers. If you’re based in the United States and aren’t sure where to start, check out SAMHSA’s Behavioral Health Treatment Services Locator or call their free national helpline 24/7 at 1-800-662-HELP (4357).

Here are some other ways to find a therapist:

- Sidran Institute’s Help Desk can help you find therapists who specialize in trauma treatment
- American Psychiatric Association’s Psychologist Locator
- ADAA Therapist Directory

For veterans: Learn more about PTSD treatment through the Department of Veterans Affairs
For veterans and their families: NAMI’s free suite of mental health resources
Or talk to your healthcare provider for recommendations

Dr. Brian Pilecki is a clinical psychologist at Portland Psychotherapy specializing in psychedelic-assisted therapy and treating anxiety disorders, trauma, and PTSD. He graduated from Fordham University and completed a postdoctoral fellowship at the Warren Alpert Medical School of Brown University.