Discover how alcohol impacts your body’s processes and causes hangovers, and find out what causes the most common hangover symptoms. -- The molecule responsible for hangovers is ethanol, which we colloquially refer to as alcohol. Ethanol is present in all alcoholic beverages, and generally speaking, the more ethanol, the greater the potential for a hangover. So, how exactly does alcohol cause a hangover— and is there any way to prevent one? Judy Grisel explores the surprising ways that alcohol affects the body. Lesson by Judy Grisel, directed by Anton Bogaty.