Where Did the Phrase “In Stitches” When We Laugh Hard Originate and What Does the Expression Mean?

Like the stitches in sewing, those in the side from both running and laughing all come from the verb stick.

The expression “to stick someone” is over a thousand years old and means “to stab” or “to prod.”

The stabbing or sticking of a needle through cloth in sewing is thus called a stitch.

And because both the pain in the side from running and that from laughing feels like you’ve been stabbed or stuck with something, these too are called stitches.