CHECK-UP:How do bruises form and why do some people bruise easily, asks MARION KERR
I’m 12 years old and always seem to be getting bruises. I’ve often wondered what bruises are.
Although bruises can develop for a number of reasons, they are most commonly caused by bumping into something or falling.
A bruise occurs when the muscle fibres and connective tissue underneath the injured area are crushed but the skin does not break.
As a result, the small blood vessels near the surface of the skin get damaged and blood leaks out.
Because the blood has no where to go it gets trapped under the skin.
Bruises can be quite painful to touch but, as you have probably noticed they eventually go away and don’t leave a permanent mark.
People who are very active or who play a lot of sport often have a lot of bruising.
But if you are worried about your bruises you should talk to your mum or dad, or other adult about it.
Why do bruises change colour over time?
Over about two weeks, the body breaks down and reabsorbs the leaked blood from under the skin. In the first day or two a substance called haemoglobin, which carries oxygen in the blood, changes colour causing the bruise to change from its initial red colour to purple/blue or even to black. As the body reabsorbs the leaked blood, the bruise turns yellow or green after about five to 10 days. After this time, it is often brown and eventually fades away after about two weeks.
My grandad gets a lot of little bruises on his hands and arms and he’s not as active as I am. Why does this happen?
How easily we bruise depends on a number of things including how tough our skin is, whether a person is taking certain medications or tablets or whether someone has a disease or condition that makes them bleed more easily.
Older people can bruise more easily because their skin is thinner and they have lost the protective layer of fat from under the skin that helps protect blood vessels from injury.
As well as that, the blood vessels of older people can be more delicate and break more easily. This means that even a minor bump can result in a very big bruise. Some tablets that older people have to take can cause them to bleed more easily.