Post Traumatic Stress Disorder

Medically reviewed by Carina Fung, PharmD, BCPPS

What is PTSD?

Post-traumatic stress disorder1, or PTSD, is a mental health disorder that develops in some people after experiencing or witnessing a terrifying, shocking, or dangerous (traumatic) event.

PTSD has been called many different names2 throughout history, usually in reference to combat veterans. Many soldiers who returned home from World War I were thought to have “shell shock,” while veterans of WWII experienced what was known as “combat fatigue.” But PTSD doesn’t just affect those who have served in war — it can occur in anyone, at any age.

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It’s normal to feel shaken up — or even go into shock — after a traumatic event. When in the presence of danger, your “fight or flight” response triggers a chain of instantaneous changes in the body. This reaction helps you avoid or defend yourself against harm.

In people with PTSD, the regions of the brain that trigger and regulate the fight or flight response have been thrown out of balance. As a result, certain situations, sensations, and experiences continue to trigger the fear response well after the initial traumatic event has occurred.

While everyone responds differently to trauma, most people recover from their residual symptoms with time, self-care, or counseling. Those who develop PTSD, however, may continue to feel distressed, frightened, or threatened, even with no immediate danger present. They may experience flashbacks (vivid recollections of the traumatic event), nightmares, severe anxiety, and uncontrollable thoughts about the event.

The symptoms of PTSD can last for months or years, become more severe, and interfere with daily life. Receiving effective treatment, however, can improve the disorder’s symptoms and help restore normal daily function.

Complex PTSD

Complex PTSD3 is a form of PTSD that may be diagnosed in people who have experienced repeated traumatic events, such as ongoing violence, neglect, or physical or emotional abuse.

The symptoms of complex PTSD are similar to those of PTSD in general, with the possible addition of:

  • Feelings of guilt or shame
  • Difficulty controlling emotions
  • Dissociation: periods of lost concentration and disconnect from one’s thoughts, feelings, memories, or sense of self
  • Physical symptoms, such as dizziness, headaches, chest pain, and stomach aches
  • Isolation and separating oneself from family and friends
  • Strained personal relationships
  • Risky or self-destructive behavior, including self-harm, alcohol abuse, or drug abuse
  • Suicidal thoughts or attempts

Complex PTSD is generally thought to be more severe if:

  • The trauma/traumatic events occurred early in life
  • The trauma was caused by a parent or caregiver
  • The trauma was experienced over a long period of time
  • The person suffering the trauma was alone while it was occurring
  • The person who experienced the trauma is still in contact with the person who caused it

It may take years to recognize the symptoms of complex PTSD, making it difficult for people with the condition to receive effective, timely treatment. Because of this, children who experience repeated trauma may show altered development, including behavior and self-confidence, as they grow older. Adults with complex PTSD may have difficulty trusting people and may feel isolated from others.

Combat exposure and PTSD

Military service members and civilians are exposed to numerous potentially traumatic events during war, combat, or conflict. Research has indicated a strong link between high levels of combat stress4 and the development of PTSD.

Service members may develop PTSD as a result of engaging in or witnessing a number of traumatic events. They are at risk of death and injury, and may see others hurt or killed. They may have had to hurt or kill other people. Service members must be alert at all times. These factors combined can increase the chances of developing PTSD or other mental health problems.

How common is PTSD?

Anyone can get PTSD, and the condition can develop at any time in one’s life.

More than 8 million American adults have PTSD, and 3.6% of the adult population experienced PTSD in the past year. According to the National Center for PTSD, roughly 7 or 8 people5 out of 100 will experience the condition at some point in their lives.

Some people at risk for developing PTSD are war veterans and those who have experienced physical or sexual assault, abuse, serious accidents (such as car crashes), disasters (including natural disasters or acts of violence/terrorism), and other serious events. Women are also twice as likely6 as men to have PTSD.

According to the Anxiety and Depression Association of America, 67% of people7 exposed to mass violence have been shown to develop PTSD — a higher rate than those who experience natural disasters or other types of traumatic events.

What causes PTSD?

PTSD can develop after someone has experienced, seen, or learned about a traumatic event. Not everyone with the condition develops it after going through a dangerous event. Some people may develop PTSD if a close friend or family member goes through a traumatic experience or if a loved one passes away suddenly or unexpectedly.

Researchers aren’t sure exactly why some people develop PTSD and others don’t. As is the case with most mental health disorders, the condition likely develops8 due to a complex combination of:

  • Inherited mental health risks, such as a family history of depression or anxiety disorders
  • “Temperament”: the inherited features that make up your personality
  • The amount and severity of trauma you’ve experienced throughout life

Research has also shown that differences in the way structures in the brain regulate the chemicals and hormones responsible for stress responses may contribute to your likelihood of developing PTSD.

The symptoms of PTSD develop due to dysfunction9 in two key regions of the brain: the amygdala and the prefrontal cortex (PFC).

The amygdala is a small, almond-shaped structure found deep within the middle of the temporal lobe. This structure’s job is to:

  • Detects threats in the environment and activate the fight or flight response
  • Activate the sympathetic nervous system to help you deal with the danger/threat
  • Help store new emotional or threat-related memories

The prefrontal cortex, or PFC, is found in the brain’s frontal lobe, just behind your forehead. Its job is to:

  • Regulate emotions
  • Initiate conscious, voluntary behavior
  • Regulate attention and awareness
  • Make decisions about the best responses to different situations
  • Inhibit or correct dysfunctional reactions to situations
  • Assess the meaning or emotional significance of events

When your brain detects a threat or potential danger, the amygdala initiates a quick, automatic defensive response (the fight or flight response, or stress response10). This triggers a release of chemicals that kick the body into high gear.

After epinephrine (adrenaline) is released into the bloodstream, the heart starts to beat faster than normal, providing extra blood to the muscles, heart, and other vital organs. Blood pressure increases and the small airways in the lungs widen, allowing you to take in as much oxygen as possible. This extra oxygen is sent to the brain, which increases alertness. The release of epinephrine also triggers glucose (blood sugar) and fats to be released from the body’s temporary storage sites, supplying the body with extra energy.

At the same time, the medial prefrontal cortex consciously assesses the level of threat present. Depending on this assessment, the PFC decides to either heighten or diminish the fight or flight response.

People with PTSD have been shown to have a hyper-reactive amygdala and a less active medial prefrontal cortex. In other words, the amygdala reacts excessively to potential threats, while the medial prefrontal cortex is unable to properly assess and regulate the stress response. This causes hyperarousal, reactive anger and impulsivity, increased fear and anger, and decreased positive emotionality.

Risk factors for PTSD

While anyone can develop PTSD, some factors11 may increase your risk of developing PTSD following a traumatic event. These risk factors include:

  • Experiencing trauma early in life (such as childhood abuse)
  • Experiencing intense and/or ongoing trauma (often leads to complex PTSD)
  • Having other mental health conditions, such as depression or anxiety
  • Having blood relatives with related mental health conditions
  • Working a job that increases your risk of being exposed to traumatic events, such as being in the military or serving as a first responder
  • Lack of a strong support system of family and friends (especially right after experiencing the traumatic event)
  • Substance abuse or dependence, such as alcohol or drug abuse

It’s important to remember that not everyone who experiences traumatic events will develop PTSD. In fact, most people who do will not develop the disorder. Ultimately, whether you are likely to develop PTSD following a traumatic event depends on both personal risk factors (such as pre-existing mental health conditions) and external circumstances (the type and duration of trauma experienced; support system after the trauma), as well as “resilience factors” (which may reduce your risk for the disorder).

PTSD symptoms

The symptoms of PTSD fall into four main categories12: intrusive thoughts and memories, avoidance, negative changes in thinking and mood, and changes in physical and emotional reactions.

Each symptom of PTSD can range in severity from person to person, from mild to serious and debilitating. While symptoms generally start within a few days to one month13 after the initial traumatic event, they may not appear in some people until several months or years after the event occurred.

Intrusive Memories

  • Flashbacks: vividly reliving the traumatic event as if it were happening again
  • Recurrent, upsetting memories of the event
  • Distressing dreams or nightmares about the event
  • Severe emotional or physical reactions to sights, sounds, sensations, or situations that remind you of the event


  • Avoiding reminders of the traumatic event, including places, people, objects, activities, and situations that trigger distressing memories
  • Avoiding thinking or talking about the event
  • Difficulty or resistance toward talking about feelings around the event

Negative changes in thinking and mood

  • Memory problems, such as not remembering key aspects of the traumatic event
  • Negative thoughts about yourself, others, life, or the world
  • Persistent fear, horror, anger, guilt, or shame
  • Feelings of hopelessness
  • Isolation or detachment from family and friends
  • Strained close relationships
  • Difficulty experiencing happiness or other positive emotions
  • Feeling emotionally “numb”
  • Lack of interest in activities you used to enjoy

Changes in physical and emotional reactions (also called “arousal symptoms”)

  • Constantly looking out for danger
  • Being easily startled or frightened; feeling “on edge”
  • Trouble sleeping
  • Trouble concentrating
  • Self-destructive behavior, such as alcohol or drug abuse or self-harm
  • Irritability, outbursts of anger, or aggressive behavior

The symptoms of PTSD can vary in intensity over time. You may experience more severe symptoms when you are stressed or if you encounter reminders of your trauma.

If you think that you or a loved one may be experiencing PTSD, talk to a healthcare provider. They will be able to diagnose and properly treat the signs and symptoms of the condition.

PTSD in children

Children and teenagers can exhibit extreme reactions to traumatic events. Older children and teens are more likely than younger children to show symptoms of PTSD similar to those seen in adults. Sometimes, they may also develop disruptive, disrespectful, or destructive behaviors.

The signs and symptoms of PTSD in children14 younger than six years old may be different than those of older children, and can include:

  • Wetting the bed (after already being potty trained)
  • Forgetting how to speak or being unable to talk
  • Re-enacting the traumatic event or aspects of the event through play
  • Frightening dreams or nightmares, which may or may not include aspects of the event
  • Being abnormally clingy with a parent or other adult

If you or someone you know is experiencing suicidal thoughts, call the National Suicide Prevention Hotline at 1–800–273–8255 or text HOME to the Crisis Text Line at 741741.

You may also reach out to the Samaritans: Call or text (877) 870-HOPE (4673).

Disclaimer: The information on this site is generalized and is not medical advice. It is intended to supplement, not substitute for, the expertise and judgment of your healthcare professional. Always seek the advice of your healthcare professional with any questions you may have regarding a medical condition. Never disregard seeking advice or delay in seeking treatment because of something you have read on our site. RxSaver makes no warranty as to the accuracy, reliability or completeness of this information.

If you are in crisis or you think you may have a medical emergency, call your doctor or 911 immediately.