The stress‑related disorder characterized by a strong and lingering reaction to extreme stress is post‑traumatic stress disorder (PTSD).

PTSD develops after exposure to a traumatic event (such as violence, serious accidents, disasters, or combat) and is marked by persistent symptoms like intrusive memories or flashbacks, avoidance of reminders, negative changes in mood and thinking, and ongoing hyperarousal (feeling on edge, easily startled, sleep problems) that last for more than a month and cause significant distress or impairment.