Epilepsy is a nervous system condition. It causes repeated, sudden, brief changes in the brain's electrical activity. These changes cause various types of symptoms.
Epileptic episodes are called seizures or convulsions. During a seizure, brain cells fire uncontrollably at up to four times their normal rate. Seizures temporarily affect the way a person behaves, moves, thinks or feels.
There are two main types of seizures:
A primary generalized seizure involves the entire brain.
A partial seizure begins in one brain area. It affects only part of the brain. However, a partial seizure can turn into a generalized seizure.
Many conditions can affect the brain and trigger epilepsy. These include:
Brain injury, either before or after birth
Infections, especially meningitis and encephalitis
Abnormal blood vessels in the brain
In most people with epilepsy, the specific cause is unknown.