NEW YORK (PIX11) — Epilepsy affects millions of Americans but it’s still a bit of a mystery disease.

Dr. Jaqueline French said epilepsy is caused by an electric instability in a part of the brain that can erupt into a seizure, which can be a funny feeling, an emotion, a staring spell, or a temporary loss of awareness. Epilepsy can be triggered by a brain infection or tumor, the doctor said.

“Many people don’t know why they have epilepsy,” said French, who works at NYU Langone.

Approximately 3.4 million Americans have the disease and most medications are effective in treating it. November is National Epilepsy Awareness Month.

Watch the full interview in the video player above.