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What Role Does Stress Play in EMS?

Ryl stress in EMS

This is the first in a multipart series on stress and resilience in EMS.

There’s no denying a career in EMS can be stressful. We are witnesses to gunshot victims, steel-bending motor vehicle collisions, unresponsive babies, and disturbing suicides and murders.

As practitioners, what often affects us more even than what we see is our own personal associations—that suicide may remind us of our own child who struggles with mental health issues, or an elderly cancer patient may recall our grandmother battling the same diagnosis.

As the years go by, calls have a way of accumulating in the mind-space and can affect us in insidious ways. To top it off, EMS workers have to walk a tightrope of work-life balance and attempt to keep work stress at bay in their personal lives. Left unchecked, stress can manifest into more severe conditions such as anxiety and depression or lead to stress disorders such as obsessive-compulsive disorder and post-traumatic stress disorder (PTSD).

There has recently been widespread attention to mental health in first responders, and it’s about time: In Canada 46 first responders and 10 military members died by suicide in 2017 (and these are only the reported cases).1 In Australia a study concluded that 37% of paramedics suffered from some form of depression.2 In the wake of these alarming statistics, how do we protect ourselves and help ensure career longevity?

Stress: What It Is

Stress can be an ambiguous term applied to many situations. Saying “I’m feeling stressed out these days” is different than the immediate physical response of a pounding heart and sweating when someone waves a knife at you; yet both mental perception of stress and its physical effects are interconnected. 

Stress is a necessary and fundamental part of being human. In a nutshell, acute stress kick-starts hormonal and behavioral responses that allow an organism to make adaptations to environmental pressures. Chronic stress, or dysregulation of the stress system, can greatly disrupt homeostasis and lead not only to debilitating mental health disorders but also to reproductive dysfunction, growth disruption, suppressed immune function, decreased muscle and bone mass, atherosclerosis, visceral obesity, gastrointestinal disorders, and insulin resistance.3

Stress and EMS

In EMS, we have many stressors. They include workplace conflicts (colleagues, management), high call volumes, overtime, shift work, abuse of the 9-1-1 system, unstable and dynamic working conditions, skills proficiency and protocol changes. EMS workers also carry a high level of responsibility; a 2012 study of Ottawa emergency service workers found that paramedics carry the highest rate of PTSD, even more than firefighters and police.4 With responsibility, guilt can arise—and stress as a result—especially if clinical mistakes are made or patients die despite our efforts. 

Apart from workplace stress, our personal lives also have a monumental impact on our overall resilience. If we’re experiencing relationship issues, going through life transitions or the loss of a family member, or have had other traumas, we are more likely to carry that stress over on our shifts at work. We can attempt to keep our personal and work lives separate, but that can only be protective to a degree; sooner or later our personal life can begin to affect our work life, and vice versa. 

How could chronic stress affect EMS personnel? One may begin to notice an impaired memory—for example, it may take longer to recall drug calculation dosages—or impaired concentration while initiating a difficult IV or intubation. Mental focus may be fuzzy. One may become irritable and short-tempered with difficult patients or overtime calls. Coordination could even be off, and one may find themselves slipping more on icy surfaces or bumping into corners. These impairments are due to a complex interaction of many factors, including increased cortisol levels that can remain in our system for some time. 

There is no denying that changes in the ability to respond to stressors, such as in chronic states, can lead to disease. What can we do about it? Can we prevent acute stress from manifesting into chronic issues? 

HPA Axis and the Amygdala

Bill is a paramedic new to the industry. One day he responds to his first pediatric anaphylaxis call. As soon as he receives the dispatch, Bill begins to perspire. His heart rate increases, his hands begin to tremble, and his stomach feels queasy. While responding with lights and siren, Bill struggles to compose himself and has difficulty remembering weight-based dosage calculations and advanced airway adjunct sizes.

When he and his partner arrive on scene, they find a 2-year-old girl in her mother’s arms. She is centrally cyanotic and struggling to breathe. Bill freezes and feels a lump rise in his throat. His partner hands him an epinephrine vial; Bill looks at the concentration and dosage on the packaging but cannot comprehend what his brain is trying to read. 

Does any of this sound familiar? Most practitioners experience “tunnel vision” to some extent at least once in their careers. This is when the sympathetic nervous system—our “fight, flight, or freeze” (FFF) response—initiates and autonomic processes begin. Responses include increased heart and respiration rates, dilated pupils, blood shunting from the core to extremities, and a cessation of digestion. All of this happens instinctively as a survival mechanism in the face of threats or the unknown. The problem with this stress response when it is all-consuming (as happened with Bill) is that it interferes with our prefrontal cortex, or our ability to think rationally. 

Human biology is powerful. The human brain is the continuous conductor of physical functions. Inside our skulls we have a brain stem (the “reptilian” brain responsible for autonomic responses such as heart rate, respiration, and digestion), limbic system (emotional center), and prefrontal cortex (capable of conscious, rational thought). When a stressor is present, or even the thought of one, information is relayed up through the brain stem and limbic system twice as fast as the time it takes to reach the prefrontal cortex. Before we even have time to consciously respond to the stressor, problem-solve, or decide there is no real threat, our autonomic nervous system and stress response have already kicked in. After that it can become difficult to access the prefrontal cortex until our stress-response symptoms begin to abate.5

Key components of the stress system are the hypothalamic-pituitary-adrenal (HPA) axis and the autonomic nervous system (ANS). These systems interact with other vital centers in the central nervous system (CNS) and tissues/organs in the periphery to mobilize a successful adaptive response against the imposed stressor(s).3 When there is a sustained or frequent stress response, or even a perception of stress, the HPA axis is stimulated, which initiates physical responses and the release of chemicals that work together to create and condition the pathway. Over time this creates detrimental psychological effects and disease processes in the body. 

The amygdala connects to the limbic system and is one of two almond-shaped clusters of nerve cells located in the temporal lobe of the brain. It responds to information from the body’s senses and is involved with the development of the fear emotion—it presses the “panic button.”

The amygdala is connected to all parts of the brain and will send signals to the brain stem to activate the FFF response. As with the HPA axis, the amygdala will respond and even increase in physical size with persistent stressors; its neuropathways can be reinforced with its activation of the fear emotion. This can cause paranoia, an increased startle response, inability to cope, and a generally overtaxed sympathetic nervous system—symptoms that can lead to PTSD.6

Perception and Brain Training

As mentioned earlier, perceived stressors can be as important as real ones. One study enrolled 26 participants in an eight-week mindfulness course.7 (The definition of mindfulness is the nonjudgmental awareness of present-moment experiences. Participants practiced meditation techniques designed to increase awareness of present-moment experiences such as thoughts, emotions, and physical sensations. They also learned to use this awareness in responding more skillfully to stress in their everyday lives). 

Participants in the study were “stressed” but otherwise healthy. Researchers took precourse and postcourse MRI scans of subjects and correlated the scans to participants’ current perceived levels of stress. At the conclusion of the study, researchers discovered a confirmed correlation between stress level scores and a decrease in gray matter density within the right amygdala, without anything significantly changing in the participants’ lives in terms of stressors.

This demonstrated that neuroplastic changes in the brain are associated with improvements in a psychological mind-set. In other words, if one changes their perception of and reaction to stress, they can change the physical structure of their brain and will be able to respond more effectively with higher-level thinking in the face of stressors. 

One can train their brain, with both real and perceived stressors, to harness autonomic responses and allow the prefrontal cortex to problem-solve.8 One can practice engaging the cortex and working “from the top down” to condition instincts to react better in the face of fear. Without conscious practice, we can be susceptible to allowing our instincts to control fear and stress.

The next part of this series will dive into resilience, with specific techniques to practice harnessing stress and even using it to our advantage. 


With a clinical understanding of the physiology of stress and its impacts on both the body and psychological state, we can begin to reduce the stigma of stress and its effects. With this awareness we recognize that our biology is susceptible to stress—and with awareness can come change. We can learn to use biology to our advantage and practice resilience in our workplace and our lives. 


1. Tema Conter Memorial Trust.

2. Sofianopoulos S, Williams B, Archer F, Thompson B. The exploration of physical fatigue, sleep and depression in paramedics: A pilot study. Australasian J Paramed, 2011; 9(1).

3. Tsigos C, Kyrou I, Kassi E, Chrousos GP. Stress, Endocrine Physiology and Pathophysiology. In: De Groot LJ, Chrousos G, Dungan K, et al., eds. Endotext. South Dartmouth, MA:, 2016.

4. Drewitz-Chesney C. Posttraumatic stress disorder among paramedics: Exploring a new solution with occupational health nurses using the Ottawa Charter as a framework. Workplace Health Saf, 2012 Jun; 60(6): 257–63.

5. Arnsten A. Stress signaling pathways that impair prefrontal cortex structure and function. Nat Rev Neurosci, 2009.

6. PTSD UK. The science and biology of PTSD, 

7. Holzel BK, Carmody J, Evans KC, et al. Stress reduction correlates with structural changes in the amygdala. Soc Cogn Affect Neurosci, 2010 Mar; 5(1): 11–7.

8. Amen D. Change Your Brain, Change Your Life: The Breakthrough Program for Conquering Anxiety, Depression, Obsessiveness, Anger and Impulsiveness. Harmony Books, 1999.

Veronica Ryl, EMT-P, CP-C, is a Canadian paramedic who has been in the industry for 11 years. She works for a busy metropolitan 9-1-1 service as a community paramedic and on a specialized mental health team. She is also an instructor on mental health readiness.

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