What is a Seizure?

Home > About Epilepsy > Understanding Epilepsy > What is a Seizure?

Seizures and epilepsy are not the same.

A seizure happens when the normal alternating pattern of these electrical impulses are disrupted, causing them to rapidly fire all at once.

Depending on where the seizure in the brain, this can cause changes in:

  • sensation and feeling
  • awareness and consciousness
  • emotions and behaviour
  • movement

Seizures vary greatly and can be very brief or last up to two or three minutes. Most seizures are over in less than two minutes. Some seizures are severe and some very subtle.

Not all seizures are diagnosed as epilepsy.

A seizure is an event – a disruption of the normal electrochemical activity of the brain – and epilepsy is a disease of the brain characterised by the tendency to have recurrent seizures.

Under certain circumstances, anyone can have a seizure.

What is epilepsy?

Epilepsy is a common disease of the brain where there is a tendency to have recurrent seizures. It is a neurological disorder—not a form of mental illness—and seizures are caused by a temporary disruption of the electrical activity in the brain.

Approximately 3% to 3.5% of Australians will experience epilepsy at some point in their lives and over 250,000 Australians currently live with epilepsy.

Epilepsy can start at any age although it is more likely to be diagnosed in childhood or senior years.

There are many different types of epilepsies and people’s experiences differ greatly. Some types of epilepsy are age-limited and the person eventually stops having seizures. For others, epilepsy is a life-long condition.

Approximately two thirds of people with epilepsy become seizure free with medication.


The cause of epilepsy can be identified in about half of people with epilepsy, but the remaining half never find out why they have epilepsy.

Some known causes of epilepsy include:

  • head injury such as in a car accident, trauma or serious fall
  • stroke or brain haemorrhage
  • lack of oxygen to the brain for a prolonged period (such as in birth trauma, cardiac arrest, drowning, drug overdose)
  • brain infections (for example meningitis, encephalitis or brain abscess)
  • brain abnormalities at birth
  • brain tumours
  • genetic factors
  • degenerative conditions affecting the brain (such as dementia).