These occur as a result of a temporary disturbance to electrochemical activity in the brain. Neurons become unstable and fire in an erratic and abnormally rapid manner, scrambling the brain's signals and disrupting the brain's normal control of the body.
Epilepsy is said to be present when seizures become recurrent and unprovoked.
The most common disabilities or functional limitation relevant to epileptics is the consciousness limitation associated with seizures. Seizures are of various types and frequencies, and are different for each individual. These tend to affect the body in a global manner. These seizures affect a specific part of one cerebral hemisphere. In more serious forms, confusion or drowsiness may last from several minutes to several hours afterward.