What Is Posttraumatic Stress Disorder (PTSD)?

Posttraumatic stress disorder (PTSD) is a serious mental health condition that can occur after experiencing or witnessing a traumatic event. While it’s normal to feel distressed following trauma, these symptoms typically fade over time. However, if emotional and psychological symptoms persist and begin to interfere with daily functioning—such as work, school, relationships, or social interactions—it may be a sign of PTSD.

PTSD can impact individuals of all ages, including young children. It may develop after events such as physical or sexual abuse, military combat, serious accidents, or violent assaults. First responders—including firefighters, law enforcement officers, and EMTs—are especially vulnerable due to repeated exposure to life-threatening emergencies and traumatic incidents. PTSD is not a sign of weakness or personal failure; it is a natural reaction to abnormal and overwhelming experiences. Left untreated, it can lead to a wide range of debilitating symptoms, and in severe cases, even suicide.

Who Is Affected by PTSD?

Roughly 3.5% of adults in the United States are currently living with PTSD, and 1 in 11 people will be diagnosed at some point in their life. Veterans, especially those exposed to combat, are at higher risk—with 11–15% affected, and Vietnam War veterans seeing rates close to 30%, similar to those of first responders. More recently, research has shown that healthcare workers on the frontlines during the height of the COVID-19 pandemic have also developed PTSD-like symptoms.

While both men and women can be diagnosed with PTSD, women are 2 to 3 times more likely to develop the condition. Girls who experience trauma at younger ages may face greater long-term mental health challenges due to its impact on brain development. Genetics and family history also play a role, increasing susceptibility in some individuals.

What Causes PTSD?

PTSD develops as a response to trauma. The brain’s natural alarm system is designed to react to threats, and this survival mechanism becomes overactive in individuals with PTSD. Direct exposure to danger, the perception of a life-threatening event, or learning that a loved one has suffered trauma can all trigger the disorder.

Common causes of PTSD include:

Military combat
Childhood abuse or neglect
Sexual assault or rape
Ongoing exposure to violence
Stalking or being threatened
Witnessing severe injury or death
Kidnapping or being held at gunpoint
Losing a parent or guardian during childhood
Physical or psychological trauma
Major car accidents
Life-threatening medical experiences (e.g., anaphylaxis, anesthesia awareness)
Natural disasters (hurricanes, wildfires, earthquakes)
Living in conflict zones or high-stress environments
Terrorist attacks
Mass shootings

Conditions Commonly Linked to PTSD

PTSD often co-occurs with other mental health and cognitive disorders, making diagnosis and treatment more complex. Conditions that frequently occur alongside PTSD include:

Anxiety disorders
Chronic stress
Insomnia and sleep disturbances
Substance use disorders
Irritability or anger issues
Panic attacks
Cognitive difficulties or memory problems

Symptoms of Post-Traumatic Stress Disorder (PTSD)

PTSD symptoms can vary widely from person to person in both timing and intensity. Some individuals may begin experiencing symptoms shortly after the traumatic event, while for others, it may take weeks, months, or even years for symptoms to appear—often triggered by a reminder of the original trauma. In such delayed cases, it can be difficult to recognize the link between present-day distress and a past traumatic experience.

People living with post-traumatic stress disorder may experience a diverse set of emotional, psychological, and physical symptoms, including:

Intrusive thoughts, such as vivid flashbacks or recurring nightmares of the traumatic event
Gaps in memory, particularly about certain parts of the traumatic experience
Avoidance behaviors, such as steering clear of people, places, or situations that bring back memories of the trauma
Reluctance to discuss the event or share emotions related to what happened
Persistent distressing memories that disrupt daily life
Dissociation, including feeling disconnected from one’s body or surroundings
Obsessive thinking about the traumatic experience

Heightened anxiety and increased nervousness
Exaggerated fear responses
Hypervigilance or constantly feeling “on edge” and being easily startled
Emotional detachment or numbness resulting from trauma exposure
Feelings of guilt, shame, or self-blame related to the incident
Sleep problems, including insomnia or restlessness
Loss of interest in hobbies or activities once enjoyed
Frequent anger or irritability
Withdrawal from others and social isolation
Co-occurring mental health issues, such as depression or major depressive disorder