Epilepsy is a chronic disorder that causes unprovoked, recurrent seizures. A seizure is a sudden rush of electrical activity in the brain.

There are two main types of seizures:. Generalized seizures affect the whole brain. Focal, or partial seizures, affect just one part of the brain.

A mild seizure may be difficult to recognize. It can last a few seconds, during which you lack awareness.

Stronger seizures can cause spasms and uncontrollable muscle twitches and can last a few seconds to several minutes. During a stronger seizure, some people become confused or lose consciousness. Afterward, you may have no memory of it happening.