F43.0 ICD-10-CA code: Acute stress reaction
F43.0 is the ICD-10-CA code for “Acute stress reaction” in CIHI’s FY 2026–2027 release, in effect from Apr 1, 2026.
Official description
F43.0Acute stress reaction
ICD-10-CA · Canada · Also written F430
Index terms
Entries in CIHI’s alphabetical index that lead to F43.0. Searching the index by the condition the note names is how coders reach this code.
- Combat fatigue
- Shock, psychic
- Fatigue, combat
- Battle exhaustion
- State (of), crisis
- Shellshock (current)
- Crisis, acute reaction
- Reaction, crisis, acute
- Disorder (of), acute, stress
- Reaction, situational, acute
- Situational, reaction, acute
- Crisis, state (acute reaction)
- Psychosis, psychotic, exhaustive
- Exhaustion (physical NEC), battle
- Exhaustion (physical NEC), delirium
- Exhaustion (physical NEC), psychosis
- Crisis, emotional, acute reaction to stress
- Disorder (of), dissociative, brief reactive
- Disturbance, situational (transient), acute
- Situational, disturbance (transient), acute
- State (of), agitated, acute reaction to stress
- Fugue, reaction to exceptional stress (transient)
- Stupor, reaction to exceptional stress (transient)
- Panic (attack) (state), reaction to exceptional stress (transient)
- Delirium, delirious (acute or subacute) (not alcohol or drug induced), exhaustion
- Reaction, stress (severe), acute (agitation) ("daze") (disorientation) (disturbance of consciousness) (flight reaction) (fugue)
Notes for F43.0
As CIHI prints them, with any note F43.0 takes from the headings above it.
Includes
- Acute:• crisis reaction• reaction to stressCombat fatigueCrisis statePsychic shock
- Disorders of psychological developmentFrom Chapter 5: Mental and behavioural disorders (F00-F99)
Excludes
Conditions classified elsewhere.
- When associated with conduct disorder in F91.- (F92.8)From F40-F48 Neurotic, stress-related and somatoform disorders
- Symptoms, signs and abnormal clinical laboratory findings, not elsewhere classified (R00-R99)From Chapter 5: Mental and behavioural disorders (F00-F99)
Note
- A transient disorder that develops in an individual without any other apparent mental disorder in response to exceptional physical and mental stress and that usually subsides within hours or days. Individual vulnerability and coping capacity play a role in the occurrence and severity of acute stress reactions. The symptoms show a typically mixed and changing picture and include an initial state of "daze" with some constriction of the field of consciousness and narrowing of attention, inability to comprehend stimuli, and disorientation. This state may be followed either by further withdrawal from the surrounding situation (to the extent of a dissociative stupor - F44.2), or by agitation and over-activity (flight reaction or fugue). Autonomic signs of panic anxiety (tachycardia, sweating, flushing) are commonly present. The symptoms usually appear within minutes of the impact of the stressful stimulus or event, and disappear within two to three days (often within hours). Partial or complete amnesia (F44.0) for the episode may be present. If the symptoms persist, a change in diagnosis should be considered.
- This category differs from others in that it includes disorders identifiable on the basis of not only symptoms and course but also the existence of one or other of two causative influences: an exceptionally stressful life event producing an acute stress reaction, or a significant life change leading to continued unpleasant circumstances that result in an adjustment disorder. Although less severe psychosocial stress ("life events") may precipitate the onset or contribute to the presentation of a very wide range of disorders classified elsewhere in this chapter, its etiological importance is not always clear and in each case will be found to depend on individual, often idiosyncratic, vulnerability, i.e. the life events are neither necessary nor sufficient to explain the occurrence and form of the disorder. In contrast, the disorders brought together here are thought to arise always as a direct consequence of acute severe stress or continued trauma. The stressful events or the continuing unpleasant circumstances are the primary and overriding causal factor and the disorder would not have occurred without their impact. The disorders in this section can thus be regarded as maladaptive responses to severe or continued stress, in that they interfere with successful coping mechanisms and therefore lead to problems of social functioning.From F43 Reaction to severe stress, and adjustment disorders
Where F43.0 sits
- 1ChapterChapter 5: Mental and behavioural disorders (F00-F99)
- 2Block F40-F48Neurotic, stress-related and somatoform disorders
- 3Category F43Reaction to severe stress, and adjustment disorders
- 4Valid code F43.0Acute stress reaction
Source and release
- Data release
- ICD-10-CA · FY 2026–2027
- Effective date
- Apr 1, 2026
- Publisher
- CIHI
This page is built from the ICD-10-CA catalog that Vero Codes reads when it suggests codes: Canadian Institute for Health Information’s FY 2026–2027 release, imported from the publisher’s file and checked against it. The description, notes and structured data come from the same record.
Frequently asked questions
What does ICD-10-CA code F43.0 mean?
F43.0 is the ICD-10-CA code for “Acute stress reaction” in CIHI’s ICD-10-CA FY 2026–2027 release.
Where is F43.0 in ICD-10-CA?
F43.0 sits under F43 Reaction to severe stress, and adjustment disorders, within F40-F48 Neurotic, stress-related and somatoform disorders, within Chapter 5: Mental and behavioural disorders (F00-F99).
What coding notes apply to F43.0?
ICD-10-CA lists Note, Includes, Excludes notes for F43.0, including those from the headings it sits under. They are listed on this page with where each one comes from.
Which ICD-10-CA release does this page use?
It uses CIHI’s FY 2026–2027 release, in effect from Apr 1, 2026 to Mar 31, 2027. It is a reference: confirm the code against the current list and the payer’s rules before you submit it.