Epilepsy is characterized by recurrent seizures that result from abnormal neuronal activity in the brain. Seizures can be generalized, originating simultaneously across both hemispheres of the brain, or partial, originating in a localized region of the brain. Generalized seizures include absence seizures, tonic-clonic seizures, atonic seizures, and myoclonic seizures. Partial seizures can be simple, with motor, sensory or other symptoms but no change in consciousness, or complex, with impaired consciousness. Seizures can have various causes including genetic factors, head injuries, infections, or other acquired brain abnormalities. Evaluation and treatment involve diagnostic testing, medication, and management of any underlying conditions.