Why do cuts swell up?

Question

i accidentally caught the top of my finger on a knife while getting cutlery out of the draw (on the top just by the side of my nail abut half way down my nail- not that location matters)

anyway the top bit of my finger is a bit swollen, it's not infected or anything, it's just a bit puffy, like most cuts and grazes go.

i was wondering why your body reacts like that, i know it's trying to heal the cut but why does it swell? swelling has no purpose in the healing proses or is it a side effect?

thanx for your answers! x

Answer 1

It's the normal inflammation process.  Following injury to your tissues, increased movement of plasma and leukocytes from the blood into the injured tissues takes place.  This movement is achieved via the chemically-induced dilation and increased permeability of blood vessels, which results in a net loss of blood plasma. The increased collection of fluid into the tissue causes it to swell.