This document discusses crisis, crisis intervention, and the phases of crisis development. A crisis is a stressful event that disrupts homeostasis and usual coping mechanisms cannot resolve. Crises follow phases from exposure to a stressor to mounting tension if unresolved. Crisis intervention aims to resolve the immediate crisis and restore functioning. It involves assessment, planning interventions, implementing techniques like catharsis and clarification, and evaluating crisis resolution. Nurses play a key role in crisis intervention through various modalities like mobile crisis teams, telephone contacts, groups, disaster response, and education.