ABSTRACT
Normal brain function depends on a steady supply of oxygen and glucose to the organ. Impairment of cerebral circulation and/or a fall in blood oxygen or glucose will rapidly cause unconsciousness. Cerebral function may also be altered by toxic effects of gases, drugs and metabolites. Unconsciousness in a diver, during or after a dive, can result from many causes and must be treated as an emergency. Some of the causes require prompt action beyond simple first aid.
