Endorphins are the hormones in your body that help with pain?
These hormones are secreted when you are happy. Like, when you are happy, these hormones get secreted and they act as a natural painkiller.
So if you ever have a headache or are in pain, look for someone who can make you laugh like crazy. Or, you could simply do some exercise to get those Endorphins running.
And that's also where the saying "LAUGHTER IS THE BEST MEDICINE" came from.
Find Out More About Endorphins