What is Post Traumatic Stress Disorder?

Post-traumatic stress disorder (PTSD) is a psychological disorder that develops in some people after experiencing or witnessing a shocking, frightening, or dangerous event.1 Such experiences can leave a person feeling stressed, afraid, and overwhelmed. PTSD is diagnosed when these symptoms last for over one month and are interfering with an individual's daily life. This can be through having repeated and unwanted flashback memories, avoiding thinking about the traumatic experience or noticing changes in your thinking, mood, and emotional reactions. This article will continue to discuss the symptoms, causes, and treatment options for PTSD. 

Why do we get post-traumatic stress disorder?

It is very common to feel worried and scared during and after experiencing a traumatic event. This is our body's natural response to help defend and protect ourselves from danger and is known as a fight-or-flight response. Experiencing trauma can leave a person feeling a variety of complex emotions, such as feeling stressed and afraid. However, most people recover from this over time. If you continue to experience symptoms after one month of experiencing or witnessing a traumatic event, then you might be diagnosed with PTSD.2 

Signs and symptoms of post-traumatic stress disorder 

To be diagnosed with PTSD, associated symptoms must have lasted for more than one month and be interfering with an individual’s daily life - for example, impacting their ability to go out or go to work.1

Symptoms of PTSD typically begin within three months of the traumatic experience; however, some people do not experience them until years later.

PTSD symptoms are generally grouped into four types:3

  1. Intrusive memories
    • Repeated and unwanted thoughts of the traumatic experience
    • Distressing or upsetting dreams about the experience
    • Experiencing flashbacks that can be very vivid and upsetting, making you feel as if you are reliving the event
  1. Avoidance
    • Trying not to think or talk about the traumatic experience
    • Avoiding reminders of the traumatic event. For example, not going to places, doing things, or seeing people that might trigger distressing memories
  1. Changes in thinking and mood
    • Feeling detached from family and friends
    • Having negative thoughts about yourself or others
    • Feeling low mood or sad often
    • Feeling emotionally numb
    • Feeling negative emotions such as anger, horror, fear, guilt or shame
    • Memory problems where you may not recall aspects of the traumatic event
    • Finding it difficult to experience positive emotions
  1. Changes in physical and emotional reactivity
    • Feeling more irritable and having angry outbursts
    • Behaving self-destructively or recklessly, such as drinking a lot of alcohol
    • Having difficulty concentrating
    • Sleep problems
    • Always suspecting danger and feeling fearful

It is important to note that symptoms may be different for young children, including re-enacting the traumatic event when playing or having very frightening dreams of the event.

Symptoms can also vary significantly from person to person and may change in intensity over time. For example, symptoms may be more severe if you are feeling more stressed or if you have a reminder of the event.

If you are experiencing these symptoms four weeks after experiencing a traumatic event, or if you are struggling with these symptoms impacting your daily life, you should seek medical support from your GP.4

Causes of post traumatic stress disorder

PTSD is caused by experiencing a shocking, scary, or distressing event. Any situation that an individual finds traumatic can cause PTSD, and the person might not have experienced the event themselves. For example, you might have witnessed someone else experiencing something dangerous or traumatic.

Examples of these traumatic situations can include: 4

  • Serious road accidents
  • Violent assaults, such as sexual assault, robbery, or physical attacks
  • Serious health issues or conditions
  •  Childbirth experiences
  • Sudden death of a loved one

Not all people will develop PTSD after these experiences, and it is not yet fully understood why some develop PTSD and others do not. It is thought that risk factors such as living through dangerous events, feeling extreme fear, having a history of mental health difficulties, or childhood trauma may make someone more likely to develop PTSD. Protective factors are those that can help make someone resilient and reduce their risk of developing PTSD. These are thought to include seeking support from other people or support groups, having positive coping strategies, and acting effectively in fearful situations. These risk and protective factors are not fully understood and more research is needed.1

Management and treatment for post-traumatic stress disorder

Your doctor can refer you to a mental health specialist who can diagnose you and begin treatment for your PTSD symptoms.4

There are several treatment options for PTSD, and different people require different treatment approaches. Some people’s symptoms disappear with time, and others have more chronic (long-lasting) symptoms. If the trauma you have experienced is ongoing, such as being in an abusive relationship, then this needs to be addressed.1

The most common treatments for PTSD include:4

Talking therapies

Talking therapies are psychological therapies that involve guided self-help from a trained mental health professional. These therapies can be offered in different ways - in a group, individually, or online. They involve teaching people helpful and positive ways to react to the distressing events and memories that trigger their PTSD symptoms.5 The most common type of talking therapies for PTSD is cognitive behavioural therapy (CBT) or eye movement desensitisation and reprocessing (EMDR).

You can access talking therapies for free on the NHS here.5


Antidepressants are the most common medication used for PTSD, such as sertraline or paroxetine. They can help to control symptoms such as feeling sad, numb, and angry. Doctors and patients will work together to find the best medication, as well as the correct dose and combination if necessary.6

Other medications may be used to treat specific symptoms, for example to lower anxiety and help with sleep problems.

The treatment approach often depends on the severity of PTSD symptoms, and the timeline related to trauma. Most people receive a combination of talking therapies and medications. However, some may need to try different treatment options to find which approach works best for them.


How is post-traumatic stress disorder diagnosed?

A doctor with mental health experience will diagnose PTSD, such as a psychiatrist or psychologist. Adult and child diagnoses may differ, however an adult must have all of these symptoms for longer than one month:1

  • At least one intrusive memory symptom
  • At least one avoidance symptom
  • At least two symptoms related to your reactivity
  • At least two symptoms related to your thinking and mood

Many people feel symptoms similar to PTSD in the days after experiencing or witnessing a traumatic event. However, to be diagnosed with PTSD these symptoms must have lasted for more than one month, and the distress will be interfering with an individual’s daily life.3

Can post-traumatic stress disorder be prevented?

It is not possible to prevent PTSD. You cannot predict when you might experience a traumatic event, and you cannot predict how you will react and respond over time. However, there are several factors which may promote recovery after trauma and reduce the risk of developing long-term PTSD symptoms. These include:1

  • Support from friends and family
  • Joining a support group
  • Learning to feel good about your own response and your actions in moments of danger or fear
  • Having positive coping strategies or ways to learn from bad events
  • Being able to react and respond effectively when feeling fearful

These factors are complex and not yet fully understood. They interact in a very complex way, and may influence PTSD symptoms differently depending on the situation or person.

Who is at risk of post-traumatic stress disorder? 

The Charity PTSDUK has conducted research and reported the estimated risk of developing PTSD after experiencing traumatic events, such as sexual assault and the sudden death of a family member.2 You can read this information here.

How common is post-traumatic stress disorder?

It is estimated that one in 10 people in the UK will experience PTSD throughout their lives.2

People assigned women at birth are more likely to experience PTSD than men, and it is most common between the ages of 16 to 24. However, anyone can develop PTSD at any stage of their life. One in 13 children and young people suffer from PTSD during their childhood in the UK.

 However, there is limited research into the prevalence of PTSD in the UK, and estimates vary between studies.

When should I see a doctor?

Whilst it is normal to feel upset, distressed and confused after experiencing a traumatic event, most people's symptoms improve over one month.  If you are feeling symptoms of PTSD four weeks after experiencing a traumatic event you should seek medical support from your GP. You should also seek support if your symptoms are particularly worrying, and are interfering with your daily life, for example preventing you from working. Your doctor can then refer you to a mental health specialist who can help to start treatment for your symptoms.4


PTSDis a complex psychological disorder that develops in some people after experiencing or witnessing a shocking, frightening or dangerous event. There are many different symptoms that an individual can develop, including having repeated and unwanted flashback memories or avoiding thinking about the traumatic experience. These symptoms can vary from person to person, and mental health specialists can work with patients to find the most suitable treatment option. Most people receive a combination of talking therapies and medications, however some may need to try different treatment options to find which approach works best for them.


  1. Post-traumatic stress disorder [Internet]. National Institute of Mental Health (NIMH). [cited 2023 Feb 24]. Available from: https://www.nimh.nih.gov/health/topics/post-traumatic-stress-disorder-ptsd.
  2. Ptsd stats – ptsd uk [Internet]. [cited 2023 Feb 24]. Available from: https://www.ptsduk.org/ptsd-stats/
  3. What is Posttraumatic Stress Disorder (PTSD)? [Internet]. American Psychiatric Association. [cited 2023 Feb 24] Available from: https://www.psychiatry.org/patients-families/ptsd/what-is-ptsd
  4. Overview - Post-traumatic stress disorder [Internet]. nhs.uk. 2021 [cited 2023 Feb 24]. Available from: https://www.nhs.uk/mental-health/conditions/post-traumatic-stress-disorder-ptsd/overview/
  5. NHS talking therapies [Internet]. nhs.uk. 2021 [cited 2023 Feb 24]. Available from: https://www.nhs.uk/mental-health/talking-therapies-medicine-treatments/talking-therapies-and-counselling/nhs-talking-therapies/
  6. Overview - antidepressants [Internet]. nhs.uk. 2021 [cited 2023 Feb 24]. Available from: https://www.nhs.uk/mental-health/talking-therapies-medicine-treatments/medicines-and-psychiatry/antidepressants/overview/
  7. Ptsd stats – ptsd uk [Internet]. [cited 2023 Feb 24]. Available from: https://www.ptsduk.org/ptsd-stats/
This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits. See our editorial standards for more details.

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Isabella Underhill

BSc (Hons) Psychology, University of Bath

Isabella Underhill is a dedicated medical and health writer who showcased her expertise during her internship with Klarity. There, she excelled in producing scientific health articles, making complex terminologies accessible to the general reader. Her passion for psychology and mental health topics is evident in her contributions to Klarity's health library. Isabella also gained hands-on clinical experience during her placement at the Royal Free London NHS Foundation Trust. Working in Clinical Immunology and Plastic Surgery departments, she collaborated on both clinical and research aspects of patient care, emphasizing her diverse skill set in the health sector.

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