The Stress Response Following Serious Injury or Illness: A Biopsychosocial Approach


Acute stress can occur in up to 45% of injury survivors following a traumatic injury or illness. It involves an anxiety response that includes re-experience of the traumatic event, intrusive memories, dreams, and strong emotional distress on exposure to triggering events.[1] Physiotherapists can have a significant role in identifying and early management of patients who present with a stress response following serious injury/illness. Physiotherapists are not typically associated with mental health interventions, but they can have a large impact on the mental well-being of patients. However, physiotherapy is a recognised conventional profession within health care and can offer extensive ranges of physiotherapy, for example: physical activity, exercise, movement, reassurance, education, relaxation techniques and body and movement awareness. These approaches are aimed at the identification of symptoms, symptom relief, the enhancement of self‐confidence and the improvement of quality of life.

Traumatic injury is responsible for 11% of global mortality and contributes to a significant amount of physical and psychological morbidity for all age groups[2]. Patients with traumatic injury report a substantial reduction in health-related quality of life compared to other patients, including long-term psychological and physical disability. Despite the known associations between injury, depression, anxiety, ASD and PTSD, there is limited knowledge on the combined presence and extent of depression, anxiety and stress symptoms in injured patients over time[3].  Further, there is little evidence on effective early screening tools, and the implementation of screening tools, for these problems in the injured population.[3][4]

Physiology of Stress Response

Figure 1. The Stress Response.
The stress response refers to the hormonal and metabolic changes in the body following physical or emotional trauma or critical illness that cause disequilibrium and threaten homeostasis.[5][6] Homeostatic threats include arterial and venous pressure derangements, changes in volume, osmolality, pH, and arterial oxygen content. Also, temperature, pain, anxiety, and toxic mediators from tissue damage and infection can trigger the response.[6] These threats alert the central nervous system, reach the hypothalamus in the brain which then releases corticotropin-releasing hormone (CRH). This stimulates the release of adrenaline and noradrenaline from the adrenal medulla and triggers the sympathetic nervous system.[6] Heart rate and respiratory rate therefore increase in order to facilitate a greater delivery of nutrients and elimination of waste products.[6] This is the body’s stress response, commonly referred to as the ‘fight or flight’ response (Figure 1), which aims to protect the body against aggression.[6] CRH also activates the hypothalamic–pituitary–adrenal axis (HPA), which triggers the release of cortisol from the adrenal medulla to return systemic homeostasis once the threat has been dealt with.

Prolonged activation of this stress response erodes the capacity of cells and tissues to respond to changes in physiological need, and depletes metabolic reserve. The sympathetic nervous system becomes overactive in a number of diseases, and underlies mental health conditions such as anxiety, depression and chronic stress. When it is too intense and lasts for longer periods, it is associated with higher morbidity and mortality.[6] The body’s response will depend on the magnitude and duration of the stress, as well as the nutritional status of the patient.[6] It is therefore important to be acquainted with the complex mechanisms of the stress response in order to act early and prevent more harmful effects.[6]

Biopsychosocial Model

Figure 2. The Biopsychosocial Model.
The biopsychosocial model underpins physiotherapy assessments and interventions. It interconnects physiology, psychology and socio-environmental factors associated to an injury or illness and has been well established within physiotherapy for the past 25 years. It ensures physiotherapists assess and treat a patient holistically and apply intervention to help manage both physical and mental concerns.

Factors Influencing Stress Response

Internal Factors

Memories of traumatic injury or critical illness can remain prominent for patients and induce frightening recollections, nightmares and delusions.[7] Altered mental status (in the forms of both delirium and coma) is common in the ICU, and often worsened by sedation.[8] Other traumatic stressors related to the in-hospital care received include longer ICU length of stay, longer hospital stay, intubation and length of mechanical ventilation[8]. These factors may also be mediated by age, severity of illness and abruptness of onset[8].

Inability to perform everyday tasks, particularly relating to washing and toileting, may lead to frustration and embarrassment. Evidence has shown that people with physical disabilities are at a higher risk of developing psychiatric and substance disorders.[9] There is also accumulating evidence to suggest that depressive symptoms are commonly associated with increased reliance on medical services, and in turn, increase the health costs.[10]

Patients of serious injury or illness often experience pain as a result of the injury or illness and its management. Numerous neuroimaging studies have shown that brain regions activated by nociceptive stimuli can also be affected by various emotional and behavioural states[11]. Chronic pain is often comorbid with psychiatric disorders, with depression having received the most attention to date[12]. It has been observed that persons who report multiple pain conditions are more likely to experience depressive symptoms[12]. In addition, epidemiological and functional imaging studies suggest that a bidirectional relationship exists between chronic pain and mental health concerns, suggesting that not only does pain induce stress and problems with mental health, but poor mental status may influence pain[11].

External Factors

Acute bouts of stress and anxiety were identified by Kellezi et al. (2017) as common conditions affecting one’s mental health following severe illness/injury. They suggested that these conditions were commonly identified at 1 month post injury/illness, and although their prevalence decreased over time, their incidence still remains high at 12 months.[13] The combination of several external factors such as a lack of family and social support, financial and/or insurance issues, or contextual conditions (such as deployment and subsequent return home in military personnel) can lead to anxiety and depression, and impact on physical function, pain, and often affecting one’s return to work.

Family and social support play a key role in the recovery of mental health following severe injury. Family support In particular is of great importance since they provide a large portion of the care: they may offer transportation, finances, leisure, and emotional support.[14] Moreover, they are often involved in the rehabilitation goal planning, which may be adapted based on the resources available at their own home. Previous family-intervention studies reported benefits such as improvements in psychological distress, level of functioning, and employability in individuals with traumatic brain injury. Conversely, family stress and unhealthy family communication were found to impair the rehabilitation process.[15]

Insurance and compensation-seeking behaviour have also been shown to impact on psychological well-being. Previous studies showed longer lasting symptoms for compensation seekers or litigants, and can cause delayed work return as well as increased levels of psychological stress secondary to the unresolved financial issues, the injury, or a combination of both factors.[15]

Contextual factors can affect one’s psychological well-being following an road traffic accidents, for example. Being involved in an RTA can be both stressful and psychologically traumatic, and it has been reported that many individuals involved in RTA’s do not have their psychological reactions attended. This has been suggested to trigger a psychological stress response when these individuals are exposure to environments associated with the traumatic memory.[16]

Flags During Assessment

During a physiotherapy assessment, the flag system can be useful to identify any signs or symptoms that may require further attention and investigation. psycho-social flags allow physiotherapists to assess a patient holistically using a bio-psycho-social model, and direct treatment towards the needs of the patient. Orange and yellow flags can help a clinician identify signs of psycho-social struggle that may increase the risk of long-term disability, developing mental health concerns or potential misuse of medications.

Orange Flags

Orange flags are indicators of serious mental health problems and represent the equivalent to red flags of mental health. They can help indicate psychopathology such as schizophrenia, clinical depression, post-traumatic stress disorders or personality disorders. Identifying these will require the patient to be referred for a specialist psychiatric assessment. This can be screened using a patient health questionnaire-2 (PHQ-2)[17]

Yellow Flags

Psycho-social concerns can be identified through yellow flag indicators; this will identify concerning thoughts, feelings and behaviours linked to the stress of their recovery, change in lifestyle, and social context which may influence a patient’s state of mental health. These include any unusual emotional responses such as increased worry, fear and anxiety, or unusual pain behaviours such as poor coping strategies, avoidance behaviours and over-reliance of passive treatments such as medications. These will be particularly important to monitor if a patient has had an injury/illness that is life changing.

Yellow Flag Signs
Work Place -          Belief that all pain must be abolished before attempting to return to work or normal activity

-          Expectation/fear of increased pain with activity/work

-          Poor work history

-          Unsupportive work environment

Attitudes and beliefs -          Belief that pain is harmful, resulting in avoidance and poor compliance with exercise

-          Catastrophising, thinking the worst

-          Misinterpreting bodily symptoms

-          Belief that pain is uncontrollable

Social/family -          Overprotective partner/spouse

-          Socially punitive partner/spouse

-          Lack of support to talk about problems

Behaviours -          Passive approach to rehabilitation

-          Use of extended rest

-          Reduced activity with withdrawal from activities of daily living

-          Avoidance of normal activity

-          Impaired sleep because of pain

-          Increased intake of alcohol or similar substances since the onset of pain

Affective/Emotions -          Depression

-          Feeling useless

-          Irritability

-          Anxiety about heightened body sensations

-          Disinterest in social activity

Adapted from New Zealand acute low back pain guide (2004).

The Role of the Physiotherapist

The link between physical health and mental health is widely accepted, yet many health professionals have reported being under-prepared to manage both the physical and the mental health needs of patients. Physiotherapy is considered to be integral to the treatment of the physical aspects of musculoskeletal, cardio-respiratory, and neurological conditions, and it plays a significant role in managing chronic pain and preventable diseases.[18] Even when patients have no co-morbid mental health issues, health professionals working in a variety of care settings, including physiotherapists, provide reassurance, psychological support, and education to reduce distress and promote behavioural change.[19] Any treatment regime needs to take a holistic approach to both the physical injury itself and the adversity induced by it. Recovery from injury, illness, surgery or any life stress requires two key factors:

  1. Diagnosis and targeted effective treatment for the cause of the problem.
  2. Identify and minimise barriers to treatment and addressing psycho-social factors and what to do with them.

Diagnosis and Targeted Effective Treatment for the Cause of the Problem

Targeted treatment comprises of either a specific exercise program for functional purpose or surgery followed by rehabilitation. Simple, classical medical intervention is based on reductionism (knowing which structure is faulty and fixing it). This is a proven method and is ideal, however, there is often no clear diagnosis, or treatment is not as effective as intended. These and other factors can create barriers to recovery.

Identify and Minimise Barriers to Treatment and Addressing Psycho-Social Factors and What to Do with Them

Physiotherapists should look at the whole person, their circumstances and how they react to the stimulus or threat associated with their injury. These factors have the biggest influence on recovery from injury but are almost completely neglected in modern medicine. All good clinicians are aware of how these barriers can negatively affect recovery outcomes, and how much of a challenge it can be to change them. Managing your internal and external environment requires a lot more time and effort because some barriers to recovery are related to long held beliefs and behaviours that are engrained into our daily lives. Changing these can require a big effort for some patients, but can result in positive and long-term change.

To gain the best possible outcome from any adversity or stress, both systems need to be engaged. Rehabilitation is not a procedure or medication, it is a process with many layers and stages, and there are a number of things that can positively or negatively influence a patient’s outcome.[20] During an assessment it is possible for the physiotherapist to identify any yellow or orange flags that may suggest that the patient has any psycho-social or mental health concerns caused by their illness or injury. If not properly addressed during treatment, these stressors and concerns can develop into a more serious mental health condition for the patient. Physiotherapists regularly come into contact with people with common stressors regardless of the setting and it is likely that this will influence engagement and response to treatment. These patients access mainstream physiotherapy and some may need reasonable adjustments. In almost all cases these stressors will not affect the ability to treat in a department.[21] As well as the health benefits of regular exercise, it is also beneficial for psychological status. Exercise reduces anxiety, depression and negative mood by improving self-esteem and cognitive functioning, and is also associated with an improved quality of life[22]. The role of the physiotherapist and the treatment provided will depend on the injury/illness that is present. Treatment should be individualised to the patient using the expert knowledge from the physiotherapist regarding the type of injury/illness.

Psychological goals of physiotherapy include:

  • Raising self-esteem and confidence
  • Improving mood and promoting well-being through a structured exercise program
  • Motivation for self-management
  • Promotion of a more positive body image
  • Reducing social isolation
  • Improving quality of life

Physical goals remain similar to those in every treatment:

  • To provide non-pharmacological treatment for pain
  • To improve muscle strength and flexibility
  • To improve cardiovascular endurance
  • Prevention of falls and other mobility issues
  • Advice on weight management. [23]

Some main findings in evidence are that: physical activity is associated with decreased risk of developing clinical depression, aerobic and resistance exercises are effective for treating depression, the effect is of the same magnitude as psycho-therapeutic interventions. Similarly, exercise has a moderate effect on reducing anxiety and can improve physical self-perceptions and self-esteem. Aerobic and resistance exercises have been best evidenced to reduce stress through an exercise-induced increase in blood circulation to the brain and release of endorphins. This increased blood flow has an influence on the hypothalamic-pituitary-adrenal (HPA) axis and subsequently reduces stress.[24] With regard to the brain and underlying neuro-biological mechanisms and pathways, endogenous reward and motivation circuitries that are imbedded in the limbic regions of the brain are responsible for the auto regulatory and endogenous reduction of stress. Exercise techniques clearly have an impact upon these systems. This is one of the reasons why physical activity not only improves overall physical health and strength, or physiologically reduces stress, but also increases mood and decreases psychological distress, i.e., depression or affective instability, by pleasure induction.[25] Physiotherapy provides multiple interventions for stress management; from physical activity to managing thoughts and emotions. The relaxation response is almost universally successful in obtaining better than normal recovery outcomes. Relaxation training has been proven to reduce stress levels and improve health outcomes in every condition tested. Simple relaxation, breathing and/or meditation work very well and offer a high benefit for minimal effort. Some exercises included for patients with mental health disorders that could prove beneficial for patients presenting with these stressors are: relaxed deep breathing, muscle flexibility, relaxation, endurance, biofeedback, multi-sensorial stimulation and balance training. Recently, there has been an increased amount of research on the role of mind-body types of exercise such as yoga or Tai Chi which has shown to reduce stress. Concerns whilst designing a program include structured versus lifestyle activities, individually tailored, self-monitoring, group versus individual and self-efficacy.

Things to consider during appointments with patients who present with psycho-social concerns as a result of serious injury/illness:

  • If the person has any specific likes or dislikes which may affect the appointment, in particular fears
  • The impact of their mental health on day to day life and function
  • How you will communicate, use words they may be familiar with be respectful, do not stigmatise and remember people with a diagnosis of mental illness are people just like everyone else, communication is key
  • Try and understand the wider implication of the injury and use a holistic approach
  • You may need to develop your therapeutic relationship before proceeding with a manual assessment or intervention[21]


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