Absence seizures, also known as petit mal seizures, are brief seizures that cause a lapse in awareness. They typically start suddenly, without warning, and last a few seconds. Absence seizures usually have a genetic cause, and several genes are thought to be involved. They occur most often in people under age 20, usually in children ages 4 to 12. However, less often, older teens and adults may also have absence seizures. In some cases, the seizures are triggered by flashing lights or when the person breathes faster and more deeply than usual (hyperventilates) . Unexplained difficulties in school and learning difficulties may be the first sign of absence seizures. During the seizure, the person may stop walking and start again a few seconds later, or stop talking in mid-sentence and start again a few seconds later. The person usually does not fall during the seizure. Symptoms of absence seizures include a sudden stop in activity without falling, lip smacking, eyelid flutters, chewing motions, finger rubbing, and small movements of both hands. Afterward, theres usually no memory of the incident.