HEALTHFirefighter Syndrome: A Proposed Whole Systems Framework 

Firefighter Syndrome: A Proposed Whole Systems Framework 

By: B. Christopher Frueh, PhD, Jadie Miller, Gina Rudine, and Brad Wylie 

A career in firefighting involves inherent risks and dangers, including short- and long-term medical, psychological, and social strains.

Firefighters respond to and mitigate a vast range of emergency situations. These include entering burning buildings, applying emergency first aid and CPR, deconstructing vehicles to access trapped civilians, 24-hour shifts, and many other critical duties to protect and rescue the communities they serve. They risk their lives and their health every day on the job.  

Despite the debt that we (as society) owe to firefighters, there is a profound lack of medical research examining their health risks and trajectories over time. For example, a search of MedLine (an index of all medical journal articles) found only 499 medical articles about firefighters published in 2021, compared to 15,299 for veterans. That makes firefighters one of the least well understood highly-at-risk populations. Or to say it another way: We know very little about the comprehensive health, wellness, and functioning of our firefighters. 

We suggest taking a whole systems approach for firefighters that we have adapted from a  framework applied toward military special operators, known as “Operator Syndrome.”1 

1 Frueh BC, Madan A, Fowler JC, Stomberg S, Bradshaw M, Kelly K, Weinstein B, Luttrell M, Danner SG, Beidel DC. “Operator  Syndrome”: A unique constellation of medical and behavioral healthcare needs of military special operations forces. The International  Journal of Psychiatry in Medicine 2020; 55:281-295.

A Proposed Whole Systems Framework for “Firefighter Syndrome” 

A career in firefighting involves regular exposure to chronic stress, lethal risks, and potential  for a wide-range of injuries, including traumatic brain injuries and toxic exposures. The  accumulation of these physiological, physical, psychological, and neuroendocrine injuries (i.e., high  allostatic load) can lead to profound physiological changes upon the individual. This load is  different from, but similar to, that borne by military special operators (e.g., Army Green Berets,  Navy SEALs, Air Force PJs). We believe it leads to a profession-specific constellation of inter related medical, social, and psychological conditions. A whole systems framework can help us better  understand and address the complex needs of firefighters: 

1. Traumatic Brain Injury (TBI) and Toxic Exposures 

Firefighters face high risks of traumatic brain injuries, including (a) impact force injuries, and (b) toxic exposures. Impact force injuries, such as concussions, may occur due to falls, slips, structure collapse, and flying projectiles, among other events. Such closed head injuries are cumulative over the course of lifetime. Toxic environments from chemical, industrial, and residential fires and hazardous material can include among others: smoke, benzene, toluene, carbon monoxide, natural gas, carbon dioxide, oxygen deficient atmospheres, and potentially even the bunker gear protective equipment worn. All of these can cause profound and cumulative damage to the brain and every other bodily system. 

2. Hormonal dysfunction 

Many common components of the firefighting profession can lead to a disruption of healthy  hormonal function. Traumatic brain injuries and chronic stress can dysregulate the endocrine system via the hypothalamic-pituitary-adrenal (HPA) axis (i.e., governing brain structures), causing  hormonal dysfunctions such as low testosterone in men. Additionally, acute and chronic stress  contribute to the dysfunction in this process, leading to increased secretions of the stress hormones 

cortisol and norepinephrine, which has a cascading effect on the sleep cycle and other vital physical  processes. Dysfunction of the endocrine system can manifest as low testosterone, abnormal human  growth hormone (HGH) levels, abnormal thyroid issues, abnormal estrogen levels, irregular stress  hormone levels (cortisol and norepinephrine), and adrenal dysfunction. These hormonal imbalances  can lead to serious complications with sleep, mood, cognition, and energy. 

3. Sleep disturbance 

Sleep disturbance is a regular component of the firefighter’s lifestyle, as sleep schedules are  frequently disrupted, shifts are at irregular hours, and a call to action can come in at any given  moment. Common disturbances faced by firefighters include insomnia, trouble falling and/or  staying asleep, insufficient REM and/or slow wave deep sleep, chronic sleep deprivation, night  sweats, and nightmares. 

4. Obstructive sleep apnea / Central sleep apnea disturbances 

Sleep apnea is another common condition for firefighters, likely due to TBI. Obstructive  sleep apnea is caused by a blockage of the airways during sleep, while central sleep apnea is caused  by the brain failing to send appropriate signals to the muscles that control breathing. This leads to  heavy snoring, gasping for air, and/or breathing lapses during sleep, all which disrupt the sleep cycle  and cognitive processes. Sleep apnea can lead to severe health problems if untreated, including high  blood pressure, strokes, heart failure, headaches, diabetes, and depression. Although a continuous  positive pressure airway (CPAP) machine may be prescribed to improve breathing, disturbances can  still occur with CPAP use. 

5. Chronic pain, orthopedic problems, headaches 

Due to the nature of the job, firefighters often have an increased incidence of physical  injuries,both acute and chronic, such as joint, neck, or back pain and/or immobility, as well as  headaches and migraines. Research shows a connection between TBI, PTSD, and pain severity.

6. Substance use 

Substance abuse is a common habit that can contribute to a wide range of physical,  cognitive, emotional, legal, and interpersonal difficulties. Problematic substance use includes daily  alcohol use, binge drinking, use of recreational drugs, and/or prescription drugs. It is common for  

substance abuse to develop as a form of self-medicating to cope with stress, depression, anxiety, and pain. Alcohol is the most common type of substance abuse among firefighters. 

7. Post traumatic stress disorder (PTSD) 

Firefighters are at a heightened risk for PTSD due to traumatic nature of their work. Symptoms may include distressing and intrusive memories about traumatic events, physiological reactions to thoughts of traumatic experiences (such as a racing heart, chest pain, or sweating), avoidance of reminders or triggers of the traumatic experiences, such as certain people, places, situations, or activities, and chronic arousal. Hypervigilance is a major characteristic of PTSD, as well as other behavioral changes such as irritability, hostility, self-destructive behaviors, and social isolation. Mood changes can occur, ranging from emotional detachment and depressed mood to severe anxiety and heightened reactions, with common feelings of guilt, fear, mistrust, and/or loneliness. There is a relationship between TBI and PTSD. 

8. Depression 

Depression is defined as persistent feelings of sadness, hopelessness, mood swings, a loss of  pleasure or inability to feel pleasure, low self-esteem or negative thoughts about the self, changes in  appetite and weight, and suicidal thoughts or behaviors. Depressive symptoms contribute to  worsening a range of emotional, behavioral, and physical difficulties. There is an increased risk of  depression in those with a history of PTSD or TBI.

9. Anger 

Anger is closely tied to trauma and PTSD and is often a response used to cope and maintain a sense of control. It can manifest physically as hyperarousal, with muscle tension and increased heart rate. Anger can certainly be expressed in the form of physical aggression (towards self, others, inanimate objects). It can also affect thoughts and beliefs, and manifest as irritation, impulsivity, verbal aggression, self-destructive or reckless behavior, and self-loathing.  

10. Worry, restlessness, stress reactivity, panic attacks 

The chronic stressors of firefighting can lead to anxiety. Common indicators are restlessness  or an inability to relax, heightened reactivity to minor stresses, excessive rumination or worrying,  fear of separation or abandonment, claustrophobic feelings or a strong desire to flee the scene, and  panic attacks.  

11. Marital and family dysfunction 

The firefighting profession has a high divorce rate, due in part to physical, emotional,  interpersonal, and financial stressors. Marital or family dysfunctions can develop due to anger,  depression, anxiety, discomfort with emotional intimacy, sexual dysfunctions, the desire for social  isolation, etc. Family difficulties can aggravate other areas of life and have cumulative effects on  issues with sleep, substance abuse, anxiety, depression, PTSD, and pain. 

12. Problems with sexual health and intimacy 

Stressors from firefighting can lead to an increased risk of intimacy issues and sexual  dysfunction. Sexual dysfunction can present as having a low sex drive, genital or erectile dysfunction,  or other issues related to endocrine dysfunction such as low testosterone. Other physical and mental  

challenges mentioned here can also affect this area and lead to risky sexual behavior, changes in  sexual behavior, or discomfort with sexual intimacy.

13. Being “on guard” and hypervigilant 

Hypervigilance is a vital tool for firefighters on the scene of a call – because they need to stay alert to dangers – but can be challenging to turn off outside of emergency situations.  Hypervigilance outside of high-intensity situations can be noted with feelings of being on guard, aggressive, or hyper-aroused at home, in public, in non-emergent work settings (e.g., at the firehouse), and even while driving or walking. It can be challenging to relax in safe situations or to wind down for sleep. Hypervigilance sustained for long periods of time becomes exhausting to maintain and can cause cascading physical and emotional concerns. 

14. Memory, concentration, cognitive impairments 

Many aspects of firefighting can lead to cognitive impairments. Long-term shift work, sleep deprivation, toxin inhalation, exposure to trauma, TBI, depression/PTSD, and substance abuse can all play a role in the development of cognitive deficits. Some noticeable issues include poor memory, poor attention and concentration, impulsivity, impaired planning and problem solving, sudden confusion, and easily getting lost. These problems in turn affect stress, adaptability, and performance both at work and at home, increasing the risk of accidents and injuries to the self or to others. 

15. Perceptual system impairments 

Issues with perception and the sensory system can develop in connection to TBI, toxic exposure, and other physiological stressors. Common impairments include difficulties with balance,  dizziness, vertigo, blurry and double vision, hearing loss, tinnitus (ringing in the ears), and an altered  sense of smell. 

16. Disrupted hydration and nutrition 

Observable shifts in nutrition needs and symptoms of dehydration are common. This can lead to a wide range of disturbed physical states, including chronic muscle cramping, unusual headaches, frequent heart palpitations (that are not anxiety-related), frequent decreased urine output, 

frequent fast urination after fluid intake, gout, digestive disorders, unexpected changes in weight or  body shape, a decrease in muscle mass, urological problems, and constipation or the development of  bowel disorders. Each of these has potential to do both short- and long-term harm to physical  health and functioning. 

17. Home to work transition difficulties 

Challenges often arise in the transition between home and work life. Some firefighters can feel disconnected from home life and miss the intensity and adrenaline rush of work, or face other difficulties with civilian culture, such as having trouble with daily routines or being overwhelmed by family demands. It can also be complicated to detach from work between shifts, such as “bringing the work home with you.”  

18. Existential concerns 

Existential concerns can arise after experiencing traumatic events such as the death of a  comrade, or being unable to save a down/trapped responder or a citizen considered viable. Such  experiences can lead to feelings of survivor’s guilt, remorse, a fear of death, a loss of personal  identity/mission, a loss of concern for personal life safety, and a mindset that discounts the future. 


Firefighters experience chronic stress, dysregulated sleep schedules, physical danger, and potentially traumatic experiences as an inherent aspect of their profession. The whole systems framework we propose considers multiple relevant and interrelated domains of health, wellness, and functioning. Modern medicine and society have placed too much emphasis on PTSD, but that is only a small part of a much larger problem. “Firefighter Syndrome” involves pathophysiological injuries at the molecular and cellular level of every system in the body, interacting adversely with behavioral and social functioning. 

Each of the individual conditions we describe can be evaluated and tracked over the course of a firefighter’s career. Moreover, each condition can be addressed via lifestyle modifications and professional treatments. In other words, there are clinically actionable targets if we are paying attention. Pragmatic approaches involving wearable technology, lab tests (e.g., blood and other biomarkers), tracking of signal events (head injuries, types of calls, etc.), and periodic symptom questionnaires combined with machine-learning analytics could be used to establish individual benchmarks, monitor health and functioning, track potential changes over time, and inform individual firefighters when interventions are necessary. 

Benefits to firefighters would include individualized feedback to enhance performance, early identification of developing health and social problems (potentially to include life threatening illnesses such as cancers, respiratory diseases, autoimmune disorders), improved quality of life, and better health. Improved health and performance of firefighters will bring cost-benefit savings to departments and society, including improved firefighter performance, better civilian protection, career longevity, intra-crew relationships and crew efficiency, reduced absenteeism, and savings in long-term medical and disability costs. Obviously much more research is needed to delineate and refine this framework, and to develop the solutions required. 

Barros B, Oliveira M, Morais S. Firefighters’ occupational exposure: Contribution from  biomarkers of effect to assess health risks. Environment International 2021; 156: 106704. Frueh BC, Madan A, Fowler JC, et al. “Operator Syndrome”: A unique constellation of  medical and behavioral healthcare needs of military special operations forces. The International Journal  of Psychiatry in Medicine 2020; 55:281-295.

Torres VA, Strack JE, Dolan S et al. Identifying frequency of mild traumatic brain injury in  firefighters. Workplace Health and Safety 2020; 68: 468-475. 

About the Authors 

B. Christopher Frueh, PhD is Professor of Psychology, University of Hawaii-Hilo, and Co-Founder & Scientific Director, PYROC; Jadie Miller is Founder & CEO, PYROC, and Firefighter (15 years); Gina Rudine is an undergraduate student at the University of Hawaii-Hilo; Brad Wylie is Co-Founder & Business Development, PYROC.