Stress dosen't cause epilepsy, as she said, but I know that stress can bring on a sez. This has happened to me before. I try not to let things bother me, and try to avoid stressful situations. My mother asked if I wanted to go shopping today (black friday), and I told her straight out no! I would be laying in the middle of the ladies clothing dept having a sez if I would have gone out today.
I avoid stressful situations as much as possible. If you think you are having sez, they could be brought on by stress. I'd ask your dr and see what might be going on with you.
I don't know if there really is any one MAIN cause of epilepsy. Genetics play in part, trauma (to the brain) can play in part. Reaction to injections (booster shots) that are used for all of children have been blamed. Swelling of brain (thus no room) causing slight bruising, from illness can be cause in some cases.
There are many potentials. Each case is different. Inherited epilepsy is only around 1%, so VERY VERY small. Caused by other diseases or conditions, such as mine where a tumor was in the brain. We could not find the disease on either side of the family; so most likely it was from genetic mutation how I received it.
As the others said about seizures... There are MANY potentials for triggering seizures. That also depends on the patient. Stress can with some patients, florescent lighting (how they cycle); even strobe lights can be a problem for that minority. There are others as well but thats all I'll mention.
P.S. I'll tag this on as an afterthought. Diabetics can have seizures, but they are NOT epileptic. Their episodes are caused due to the insulin levels in the body.