Question: Why is it when hurt youself the surface of your skin bruises?

Christina Pagel answered on 19 Jun 2013:

When you bump yourself the tiny little blood vessels near the surface of your skin (called capillaries) burst and you bleed a little under your skin… as the blood breaks down this turns from red to purple to black and then to yellow before finally it’s all absorbed by your body and you’re back to normal again!