Why Do Humans Cry?

Have you ever stopped for a second and wondered why, when you’re sad, liquid spills out of your eyeballs? It’s even stranger when you consider this: Humans are the only species that cries. While crying doesn’t always feel great in the moment, it’s one of many tactics your body uses to protect itself.

Turns out, there are three kinds of tears, so those shed while cutting onions are not the same type as those shed during a breakup. And crying is more than just a knee-jerk reaction — each type of tear serves a purpose, from lubricating your eyeballs to relieving pain. Learn more about why humans cry in the Yahoo Health video above.

Up Next: Why Do We Have Eyebrows?

Let’s keep in touch! Follow Yahoo Health on Facebook, Twitter, Instagram, and Pinterest.