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Hypoxic Ischemic Encephalopathy

(Cerebral Hypoxia; HIE)


Hypoxic ischemic encephalopathy (HIE) is a brain injury. It happens when the brain does not get enough oxygen.
HIE can cause death. Brain cells start to die after 4 minutes without oxygen.
Blood Supply to the Brain
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Many health problems can a lack of oxygen to the brain. Some common causes are:
  • Cardiac arrest
  • Blocked or ruptured blood vessel
  • A blocked airway due to:
    • Swelling, such as from an allergic reaction
    • Trauma
    • Drug use and drug overdose
    • Drowning
    • Choking
  • Carbon monoxide or cyanide poisoning

Risk Factors

Any injury or health problem that causes the brain to have a drop in blood flow and oxygen is a risk factor for HIE.


You may have:
  • Mild symptoms:
    • Focus problems
    • Problems making decisions
    • Clumsiness
    • Strong feelings
    • Excess drowsiness
  • Severe symptoms:
    • Seizures
    • Loss of consciousness
    • Blue-colored skin or lips
    • Problems breathing


A physical exam will be done. A health history is the biggest factor in making the diagnosis.
Blood tests may be done.
Pictures may need to be taken of your body. This can be done with:
Your heart and brain may be tested. This can be done with:


Treatment depends on the cause of HIE. It also depends on how severe the damage is to the brain.
You may have:
  • Life-sustaining treatment—If brain function stops, but damage is not great, then life saving treatment is given. This may include CPR .
  • Cooling—Cooling blankets or other means of cooling may be used to lower the body's temperature.
  • Temperature control—Cooling and rewarming the body.


HIE can’t be prevented.


Brain Injury Association of America
National Institute of Neurological Disorders and Stroke


Health Canada
Ontario Brain Injury Association


Hypoxic ischemic encephalopathy (HIE). Neurographics website. Available at: Accessed June 22, 2018.
Itoo BA, Al-Hawsawi ZM, Khan AH. Hypoxic ischemic encephalopathy. Incidence and risk factors in North Western Saudi Arabia. Saudi Med J. 2003;24(2):147-153.
MacDonald S. Brain injury secondary to carotid intervention. J Endovasc Ther. 2007;14(2):219-231.

Revision Information

  • Reviewer: EBSCO Medical Review Board Rimas Lukas, MD
  • Review Date: 05/2018
  • Update Date: 06/22/2018
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