• Question: Why do we bruise?

    Asked by noscope900 to Callum, Sam on 23 Nov 2012.
    • Photo: Sam Godfrey

      Sam Godfrey answered on 23 Nov 2012:

      When we take a knock, the blood vessels break and form a large blood clot under the skin. Initially this is a red mark, then it goes dark like a scab. That is the start of the bruise. The longer the bruise is there, the more the blood gets broken down. As blood contains iron, this means that the iron is being changed as well and Iron can form loads of colours. So the bruise goes from blue to yellow before it fades.

    • Photo: Callum Johnston

      Callum Johnston answered on 23 Nov 2012:

      A bruise is caused when the blood vessel, but not the skin is burst, so instead of the blood leaking out it builds up under the skin. This blood causes the blue and purple colours, and because it flows into an area where it shouldn’t be it puts pressure on the nerve endings causes the pain. As the blood is broken down by immune cells the colour gets less dark and can sometimes go yellow and even green!

Comments