Coma is defined as a loss of consciousness and awareness of the environment with preservation of autonomic functions. Coma is caused by dysfunction of the reticular activating system and cerebral cortex, with the most common causes being toxic or metabolic disorders, trauma, and stroke. The prognosis of a coma depends on its underlying cause, whether the problem can be corrected, and the duration of unconsciousness - the longer a person remains in a coma, the worse the expected outcome generally is, though full recovery is still possible even after weeks. Emergency treatment of coma focuses on maintaining airway, breathing, circulation, controlling seizures, and reducing intracranial pressure through medications and other interventions.