1. Letting someone blow air into your vagina.
2. Dryer lint.
3. Cleaning the bathroom.
5. Drinking too much water, too fast.
Two tragic examples: In 2005, a man died after a fraternity hazing ritual where he had to chug water from a jug over and over again. In 2007, a California woman died after participating in a water-drinking contest hosted by a local radio station. The cause of death in both cases was water intoxication, which is when someone drinks so much water in a short amount of time that the kidneys can't process it quickly enough, causing deadly swelling of the brain and lungs. It has also happened to athletes during extreme sporting events; as well as to people taking club drugs, who feel insatiable thirst and end up drinking too much water too quickly.
Stay safe: Don't ever force yourself to drink when you aren't thirsty. And don't do MDMA, Molly, or ecstasy. More information in this article in Scientific American.
6. Pools, lakes, bathtubs — any body of water, really.
7. Pressure washers.
8. Vending machines.
9. Minor cuts and scratches.
10. The flu.
11. Not getting enough sleep.
12. Shoveling snow.
13. Eating food.
14. Cheating on your wife.
This post has been updated with information about how to help someone who is choking, as advised by the Red Cross.