Cerebral hypoxia occurs when there is not enough oxygen getting to the brain. The brain needs a constant supply of oxygen and nutrients to function.

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

Hypoxic encephalopathy; Anoxic encephalopathy

In cerebral hypoxia, sometimes only the oxygen supply is interrupted. This can be caused by:

• Breathing in smoke (smoke inhalation), such as during a fire
• Carbon monoxide poisoning
• Choking
• Diseases that prevent movement (paralysis) of the breathing muscles, such as amyotrophic lateral sclerosis (ALS)
• High altitudes
• Pressure on (compression) the windpipe (trachea)
• Strangulation

In other cases, both oxygen and nutrient supply are stopped, caused by:

• Cardiac arrest (when the heart stops pumping)
• Cardiac arrhythmia
• Complications of general anesthesia
• Drowning
• Drug overdose
• Injuries to a newborn that occurred before, during, or soon after birth (See: Cerebral palsy)
• Stroke
• Very low blood pressure

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

Images

Central nervous system

Next Section

Cerebral hypoxia Symptoms

Review Date: 09/13/2010
Reviewed By: Daniel B. Hoch, PhD, MD, Assistant Professor of Neurology, Harvard Medical School, Department of Neurology, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org)