F43

F43 is an ICD-10 classification code used to categorize mental health disorders that arise in response to severe stress and to identifiable life events. The category falls within the chapter on mental and behavioral disorders and encompasses reactions to stress as well as adjustment disorders. It provides a framework for documenting how individuals respond to stressors such as violence, disaster, illness, or other traumatic experiences. The codes are used in clinical records, research, and health statistics to track prevalence, treatment needs, and outcomes.

The F43 category includes several subgroups. Acute stress reaction (F43.0) refers to a sudden onset of distress following a stressor, typically resolving within days to weeks. Post-traumatic stress disorder (F43.1) covers persistent symptoms after exposure to trauma, often including intrusion, avoidance, negative mood or cognitions, and heightened arousal. Adjustment disorders (F43.2) describe emotional or behavioral symptoms in response to a specific stressor, with subtypes such as depressed mood, anxiety, mixed anxiety and depressed mood, disturbance of conduct, or mixed disturbances of emotions and conduct. Other reactions to severe stress (F43.8) and reaction to unspecified stress (F43.9) capture less common or unspecified presentations.

In clinical use, F43 diagnoses guide assessment, treatment planning, and communication among healthcare providers. They are typically determined through clinical evaluation, consideration of duration and severity of symptoms, and the extent to which functioning is impaired. While the codes aid in standardized reporting, precise subcategorization may vary by country and over time as diagnostic practices evolve.