The Accident & Emergency (A&E) Unit sometimes termed the Emergency Room, Emergency Ward or Casualty Unit is an area of hospital or Primary Care Unit that provides initial treatment to patients with a broad spectrum of Illnesses and injuries, some of which may be life-threatening and requiring immediate attention.

Emergency Unit developed during the 20th century in response to an Increased need for rapid assessment and management of critical illnesses upon arrival; the people typically undergo a brief triage, or sorting, interview to help determine the nature and severity of their illness. Individuals with serious illnesses are then seen by a clinician more rapidly than those with less severe symptoms or injuries. After initial assessment and treatment, patients are admitted to the hospital, stabilized and transferred to another hospital wards for various reasons and further management, or discharged. The staff in Emergency Unit not only includes doctor’s but paramedics and nurses with specialized training in emergency care .

The Emergency Unit also has other Human Resource like emergency medical technicians, radiology technicians, cardiology technicians , Healthcare Assistants (HCAs), attendants and other support staff who all work as a team to manage emergency patients and provide support to anxious family members. Before making a final diagnosis; patients are attended on symptomatology and provided initial management including life saving measures. The chief complaint remains a primary record until the attending physician makes a final diagnosis with help of clinical examination, relevant lab and imaging investigations.