Recurrent unprovoked seizures are the main characteristic of epilepsy, a prevalent brain disorder that affects approximately 50 million people worldwide. Seizures are the result of uncontrolled burst of electrical activity that may emerge as the result of a brain injury or genetic mutations. Some of the mechanisms leading to seizures and the progression of epilepsy are starting to emerge. Moreover, new evidence suggests that seizures are prevalent in other brain pathologies. The impact of seizures on epilepsy and other brain disorders will be discussed.