Hypoxic-ischaemic encephalopathy (HIE)

Find out about Hypoxic-ischaemic encephalopathy, symptoms that your baby may show and treatment.

What is it?

Hypoxic-ischaemic encephalopathy (HIE) is damage to the brain caused by a lack of oxygen and blood flow getting to your baby’s brain. This happens most commonly before or during birth, when it is sometimes referred to as 'asphyxia' or 'birth asphyxia'. The process that results in HIE can also affect the lungs, liver, heart and kidneys. It is not always possible to know what causes HIE, but the resulting brain injury can be mild, moderate or severe.


Your baby may be displaying symptoms which can include: being hyper-alert, irritable, eye-rolling and having abnormal movements (fits). Your baby may also have a reduced level of awareness.


If your baby has been identified as having HIE, their treatment will depend on what level of symptoms they have. If they have moderate to severe HIE, they are likely to receive a treatment known as mild hypothermia or cooling. This is when a baby’s temperature is lowered, to limit the extent of brain injury associated with HIE.

Treatment for HIE involves placing your baby on a special cooling mattress or wrapping them in a cooling wrap; the mattress or wrap is filled with fluid that can be cooled or warmed according to your baby’s needs. Your baby’s temperature will be monitored closely to ensure that it stays at the target temperature of 33.5 degrees.

Want to read this information in print?

Order our information about HIE for free.

HIE information for parents

Download our guide to helping you understand what HIE is, what treatment options might be available and what the future might hold.