While the causes can be varied and complex, the Epilepsy Foundation offers this list of common triggers:
Missing medications, especially those used to control seizures.
Changes in sleep routines or lack of sleep.
Hormonal changes in women, such as during menstruation or pregnancy.
Abusing alcohol or drugs, or withdrawing from them.
Stress and anxiety.
Factors that unpredictably change metabolism, such as diarrhea or vomiting.