An emergency department (ED), also known as accident & emergency (A&E), emergency room (ER), or casualty department, is a medical treatment facility specializing in acute care of patients who present without prior appointment, either by their own means or by ambulance. The emergency department is usually found in a hospital or other primary care center.

Due to the unplanned nature of patient attendance, the department must provide initial treatment for a broad spectrum of illnesses and injuries, some of which may be life-threatening and require immediate attention. In some countries, emergency departments have become important entry points for those without other means of access to medical care.

The emergency departments of most hospitals operate 24 hours a day, although staffing levels may be varied in an attempt to reflect patient volume.

Lower back pain is a frequent cause of Emergency Department visits and one of the leading causes of the disease burden worldwide.

ICP monitors for intracranial pressure monitoring are frequently placed in the ED at paediatric trauma centres caring for children with severe pediatric traumatic brain injury. Both patient and organizational level factors are associated with ED ICP monitor placement.

Emergency department (ED) management of mild traumatic brain injury (TBI) with any form of traumatic intracranial hemorrhage (ICH) is variable.

Since 2000, center's standard practice has been to obtain a repeat head computed tomography (CT) at least 6 hours after initial imaging. Patients are eligible for discharge if clinical and CT findings are stable. Whether this practice is safe is unknown ¹⁾.