Cerebral hypoxia technically means a lack of oxygen supply to the outer part of the brain, an area called the cerebral hemisphere. However, the term is more typically used to refer to a lack of oxygen supply to the entire brain.

There are many causes of cerebral hypoxia. These include, but are not limited to:

• Asphyxiation caused by smoke inhalation
• Carbon monoxide poisoning
• Cardiac arrest (when the heart stops pumping)
• Choking
• Complications of general anesthesia
• Compression of the windpipe (trachea)
• Diseases that cause a loss of movement (paralysis) of the breathing muscles
• Drowning
• Drug overdose
• High altitudes
• Injuries before, during, or soon after, birth (See: Cerebral palsy)
• Strangulation
• Stroke
• Very low blood pressure

Brain cells are extremely sensitive to oxygen deprivation. Some brain cells actually start dying less than 5 minutes after their oxygen supply disappears. As a result, brain hypoxia can rapidly cause death or severe brain damage.