There are many different types of seizures. The most common is called a generalized seizure. It has also been called a tonic-clonic or grand mal seizure. Other types of seizures include petit mal seizures, partial (focal) seizures, febrile seizures and alcohol withdrawal seizures. A person may have a single seizure or repetitive seizures. People with recurrent seizures or at risk for recurrent seizures have epilepsy. A seizure results from an abnormal electrical discharge in the brain. Seizures can occur for many reasons, such as a head injury, an infection, a metabolic problem (for example, low blood sugar), a tumor, or drug use. Often the exact reason for seizures is not found.