Often, no underlying cause can be found for absence seizures. Many children appear to have a genetic predisposition to them. Rapid breathing (hyperventilation) can trigger an absence seizure.
In general, seizures are caused by abnormal electrical impulses from nerve cells (neurons) in the brain. The brain's nerve cells normally send electrical and chemical signals across the synapses that connect them.
In people who have seizures, the brain's usual electrical activity is altered. During an absence seizure, these electrical signals repeat themselves over and over in a three-second pattern.
People who have seizures may also have altered levels of the chemical messengers that help the nerve cells communicate with one another (neurotransmitters).
Absence seizures are more prevalent in children. Many children gradually outgrow them over months to years. Some children with absence seizures may also experience full seizures (tonic-clonic seizures).