Emergency medicine, formerly known in some countries as accident and emergency medicine, is the medical specialty involving care for undifferentiated and unscheduled patients with illnesses or injuries requiring immediate medical attention. In their role as first-line providers, emergency physicians are responsible for initiating investigations and interventions to diagnose and/or treat patients in the acute phase (including initial resuscitation and stabilization), coordinating care with physicians from other specialities, and making decisions regarding a patients need for hospital admission, observation, or discharge. Emergency physicians generally practice in hospital emergency departments, pre-hospital settings via emergency medical services, and intensive care units, but may also work in primary care settings such as urgent care clinics