Hypoxic Ischemic Encephalopathy

(Cerebral Hypoxia; HIE)

How to Say It: hye-POK-sik is-KEM-ik en-sef-a-lo-path-ee


Hypoxic ischemic encephalopathy (HIE) is a brain injury. It happens when the brain does not get enough oxygen.

HIE can be deadly. Brain cells start to die after 4 minutes without oxygen.

Blood Supply to the Brain

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Many health problems can cause a lack of oxygen to the brain. Some common ones 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 poisoning

Risk Factors

The risk of HIE is higher in people who have an injury or health problem that causes the brain to have a drop in blood flow and oxygen.


Problems may be mild to severe, such as:

  • Clumsiness
  • Problems with focus
  • Difficulty making decisions
  • Mood swings
  • Feeling very tired
  • Signs of seizures, such as confusion and muscle jerking
  • Loss of alertness
  • 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 brain and spinal cord may be tested. This can be done with:

Your heart function may also be tested.


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 methods may be used.


There are no known guidelines to prevent HIE.


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


Ontario Brain Injury Association


Busl KM, Greer DM. Hypoxic-ischemic brain injury: pathophysiology, neuropathology and mechanisms. NeuroRehabilitation. 2010;26(1):5-13.
Hypoxic ischemic encephalopathy (HIE). Neurographics website. Available at:
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Accessed October 1, 2020.
Hypoxic-ischemic encephalopathy in adults. EBSCO DynaMed website. Available at: https://www.dyname.... Accessed October 1, 2020.
Last reviewed September 2020 by EBSCO Medical Review Board Rimas Lukas, MD