Epilepsy is a common disorder of the brain that causes recurring seizures. Epilepsy affects people of all ages, but children and older adults are more likely to have epilepsy. Seizures are the main sign of epilepsy and most people can control this with treatment. Some seizures can look like staring spells while other seizures can cause a person to collapse, stiffen or shake, and become unaware of what’s going on around them. Many times the cause is unknown.