Why is the instinct to immediately suck on a small wound or cut, like if you smash your finger?

Question

What does this do and why do humans seem to instinctively do it?

In: Biology

Answer 1

Saliva is naturally antiseptic so is a decent way too initially treat a minor cut/graze etc. By sucking, you also apply a small amount of pressure to the wound which can help to relieve pain by allowing better blood flow to the area.