Acute Stress Reaction

Acute Stress Reaction

Definition

• Acute Stress Reaction (ASR) is a transient psychological response to an extreme stressor or traumatic event (e.g., accident, assault, natural disaster).
• It occurs within minutes to hours of the event and typically resolves within days to a few weeks.
• If symptoms persist >1 month, it may progress to Post-Traumatic Stress Disorder (PTSD).

Pathophysiology

• Exposure to a traumatic stressor triggers an acute fight-or-flight response, mediated by the hypothalamic-pituitary-adrenal (HPA) axis.
• Dysregulation of stress hormones (cortisol, adrenaline) leads to emotional, cognitive, and physical symptoms.

Common Causes of Acute Stress Reaction

Physical Trauma
– Accidents, Assault, Physical Abuse, Natural Disasters

Psychological Trauma
– Sudden Bereavement, Witnessing Death or Injury

Combat or Emergency Situations
– Military Combat, First Responders, Hostage Situations

Serious Illness or Diagnosis
– New Terminal Illness, Severe Injury

Risk Factors for Acute Stress Reaction

Previous Trauma or PTSD
– Higher Risk of Severe Reaction

Personal or Family History of Anxiety or Depression
– Pre-existing Mental Health Disorders

Lack of Social Support
– Increases Vulnerability to Psychological Distress

Neurotic Personality Traits
– Greater Emotional Reactivity to Stressors

Key Point
Severe trauma and pre-existing mental health conditions increase the risk of ASR.

Symptoms of Acute Stress Reaction

Emotional Symptoms
– Anxiety, Fear, Helplessness, Guilt, Irritability

Cognitive Symptoms
– Difficulty Concentrating, Disorientation, Intrusive Thoughts

Dissociative Symptoms
– Detachment, Emotional Numbing, Amnesia

Physical Symptoms
– Palpitations, Sweating, Hyperventilation, Tremors

Behavioural Symptoms
– Avoidance of Reminders, Restlessness, Hypervigilance

Signs on Examination

Agitation & Restlessness
– Hyperalertness, Increased Startle Response

Emotional Distress
– Crying, Irritability, Fearfulness

Tachycardia & Hypertension
– Autonomic Activation

Hyperventilation & Sweating
– Physical Manifestation of Anxiety

Clinical Insight
Dissociation, intrusive thoughts, and autonomic symptoms are hallmarks of ASR.

Referral Criteria (NICE Guidelines)

Urgent Referral

• Suicidal Ideation or Self-Harm Risk
• Severe Functional Impairment (Unable to Perform Daily Activities)
• Violent or Aggressive Behaviour

Routine Referral

• Ongoing Flashbacks, Hypervigilance, or Emotional Numbing
• Avoidance Behaviour Leading to Social Isolation
• Significant Sleep Disturbances

Important
Persistent symptoms (>4 weeks) suggest PTSD and warrant referral for psychological support.

Clinical Diagnosis (ICD-10 / DSM-5)

Exposure to Severe Stressor
– Directly Experiencing or Witnessing Trauma

Immediate Emotional Reaction
– Fear, Helplessness, or Horror

Dissociative Symptoms
– Detachment, Depersonalisation, Derealisation

Re-Experiencing Symptoms
– Flashbacks, Intrusive Thoughts, Nightmares

Hyperarousal Symptoms
– Insomnia, Irritability, Exaggerated Startle Response

Duration <4 Weeks
– If >1 Month, Consider PTSD

Differential Diagnosis

Panic Attack
– Sudden, Short-Lived (Minutes to Hours), No Trauma Preceding

Post-Traumatic Stress Disorder (PTSD)
– Symptoms Persist >1 Month, Flashbacks & Hyperarousal

Generalised Anxiety Disorder (GAD)
– Chronic Worry, No Specific Triggering Event

Depression
– Low Mood & Anhedonia Without Acute Hyperarousal

Clinical Insight
Diagnosis is clinical; PTSD should be considered if symptoms persist.

Management (NICE Guidelines)

Immediate Psychological First Aid (First-Line)

Calm & Supportive Environment
– Reduce Sensory Overload, Offer Reassurance

Encourage Social Support
– Friends, Family, Community Networks

Grounding Techniques
– Breathing Exercises, Reorienting to Present

Psychoeducation
– Explain Normal Stress Reactions & Coping Strategies

Short-Term Symptom Management

Insomnia
– Short-Term Zopiclone or Promethazine (Avoid Benzodiazepines)

Anxiety & Hyperarousal
– Beta-Blockers (Propranolol) for Autonomic Symptoms

Emotional Distress
– Short-Term Psychological Support (CBT If Persistent)

When to Consider Psychological Therapy

• If Symptoms Persist >4 Weeks (Risk of PTSD)
• If Symptoms Are Severe or Affecting Daily Life

Management Insight
Most cases resolve with psychological support; medications should be avoided unless symptoms are severe.

Prognosis

Mild ASR (Most Cases)
– Resolves Within Days to Weeks

Severe ASR
– Higher Risk of PTSD

Complications

Post-Traumatic Stress Disorder (PTSD)
– Persistent Flashbacks, Avoidance, Hyperarousal (>1 Month)

Depression
– Chronic Low Mood, Social Withdrawal

Substance Abuse
– Self-Medication with Alcohol or Drugs

Exam Insight
Early psychological intervention reduces the risk of PTSD.

UKMLA Key Points

• Best initial management: Psychological First Aid (Supportive Environment, Reassurance)
• Best long-term management: Cognitive Behavioural Therapy (CBT)
• Suspect PTSD if symptoms >1 Month with flashbacks and avoidance
• Urgent referral: Suicidal ideation, violent behaviour, severe impairment
• Pharmacology: Beta-blockers if needed, avoid benzodiazepines