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.

Revision Information

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