Cause for stitches

GASH

A deep, jagged cut might leave you needing medical attention quickly.

"Cause for stitches" hints at a deep cut or wound that would need medical attention, which is exactly what "gash" means. The clue plays on the idea that a serious injury (a gash) often requires stitches to close it up. There’s no hidden wordplay here—it’s a straightforward definition where the answer fits the scenario perfectly.