What is Epilepsy? Epilepsy is a common condition that affects the brain and causes frequent seizures. It can start at any age but is more common to start in children and those over 60. Symptoms Seizures can affect people in different ways, depending on which part of the brain is involved. a fit - uncontrollable jerking and shaking losing awareness and staring blankly into space becoming stiff strange sensations - such as a "rising" feeling in the tummy, unusual smells or tast