Viw Magazine

  • Written by Abishek Santhakumar, Senior Lecturer in Haematology, Charles Sturt University
From red, to blue, to purple, to yellow and even green – why do our bruises change colour? From shutterstock.com

How and why do we get bruises? – Francesca, aged 8.



Hi Francesca, thanks for sending in this great question.

If you fall off your bike or knock yourself on the coffee table at home, you might notice a blue or blackish spot on your skin a couple of days later. This is called a bruise (a contusion is the medical word for it, if you want to impress your friends).

When you bump into something, tiny blood vessels, called capillaries, can break under the skin. This causes the blood to ooze out of the vessel, kind of like a leaking water pipe. The blood that oozes out then collects under the skin. This is what gives a bruise its colour.


Read more: Curious Kids: How do x-rays see inside you?


Bruises can have many colours

If you get a big bruise, it will go through several colour changes before it disappears – from red, to purple, to blue, and even green and yellow.

At first, when you hurt yourself, you will have a bump on the surface of your skin. It could be a bit sore, and you might notice some redness.

The bump is because of the red cells and other fluids in the blood under the skin – that’s the stuff that oozed out of the blood vessel.

There are many ways you can get a bruise. If you fall off your bike, you might find yourself with a few bruises. From shutterstock.com

After a couple of days, the bruise will start changing into a bluish or purplish colour. The changes in colour happen because the red blood cells are breaking down. The body breaks down these red blood cells because it doesn’t need them anymore.

Finally, as the body starts to clear the unwanted red cells from under the skin, the bruise will look greenish or yellowish. It will start to fade away in about two weeks.


Read more: Curious Kids: how do wounds heal?


What should you do if you have a bruise?

Immediately after you hurt yourself – that is, when you have a bump but it’s not blue or purple yet – you might like to apply a cold pack to the sore spot for at least five to ten minutes. A bag of frozen vegetables works well too.

If the bruise is on your arm or your leg, it can be a good idea to put it up – say on a chair or on the kitchen table.

You should tell your mum or dad or see a doctor if:

  • the bruise isn’t improving or the colour is not fading away after several days
  • the bruise is swollen and very painful
  • you can’t move your leg or arm where the bruise has formed
  • you’re getting bruises very often for no obvious reasons.

Read more: Curious Kids: How does pain medicine work in the body?


It’s very hard to avoid getting bruises altogether. Especially for kids who like to run around, climb trees, and play sports. And the odd bruise is nothing to worry about.

But when you’re doing something like playing sport or riding a bike, as well as wearing a helmet, it can be a good idea to put on protective gear like knee guards, so you’re less likely to get hurt.

Abishek Santhakumar is affiliated with the Graham Centre for Agricultural Innovation, Charles Sturt University.

Authors: Abishek Santhakumar, Senior Lecturer in Haematology, Charles Sturt University

Read more http://theconversation.com/curious-kids-why-do-we-get-bruises-127994

The Role Of A Construction Supervisor On A Construction Site

Those looking into building a career in the building and construction industry are afforded a lot of options they can pursue, with responsibilities often being as diverse as the projects themsel...

News Company - avatar News Company

4 Writing Hacks You Need to Become a Great Writer

What do you need to mount up your writing skills and become a cooler writer? This venture is highly individual and relies on each particular writer’s personal abilities and expertise. However...

News Company - avatar News Company

Factors to Consider When Looking For Kid’s Birthday Party Venues

Organising huge children's birthday parties begin with finding the right kids birthday party venues. Like every other major activity that requires a bunch of guests, the final venue will dictate...

Ester Adams - avatar Ester Adams

How a Share Registry Works

Australia, the Land Down Under, is a melting pot of cultures, races, and ethnicities. This country embraces diversity and has no tolerance for discrimination of any kind, especially if it is abou...

Ester Adams - avatar Ester Adams

Has Australia really had 60,000 undiagnosed COVID-19 cases?

A preliminary study, posted online this week by researchers at the Australian National University and elsewhere, estimates 71,000 Australians had COVID-19 by mid-July — 60,000 more than official...

Andrew Hayen, Professor of Biostatistics, University of Technology Sydney - avatar Andrew Hayen, Professor of Biostatistics, University of Technology Sydney

How could wearing a mask help build immunity to COVID-19? It’s all about the viral dose

People infected with SARS-CoV-2, the virus that causes COVID-19, can spread the virus when they speak, sing, cough, sneeze or even just breathe. Scientists think face masks help limit virus spread by ...

Larisa Labzin, Research Fellow, Institute for Molecular Bioscience, The University of Queensland - avatar Larisa Labzin, Research Fellow, Institute for Molecular Bioscience, The University of Queensland

the pros and cons of different COVID vaccine technologies

ShutterstockThe World Health Organisation lists about 180 COVID-19 vaccines being developed around the world.Each vaccine aims to use a slightly different approach to prepare your immune system to rec...

Suresh Mahalingam, Principal Research Leader, Emerging Viruses, Inflammation and Therapeutics Group, Menzies Health Institute Queensland, Griffith University - avatar Suresh Mahalingam, Principal Research Leader, Emerging Viruses, Inflammation and Therapeutics Group, Menzies Health Institute Queensland, Griffith University

Government extends COVID health initiatives at $2 billion cost

The government is extending the COVID health measures for a further six months, until the end of March, in its latest acknowledgement that pandemic assistance will be needed on various fronts for a lo...

Michelle Grattan, Professorial Fellow, University of Canberra - avatar Michelle Grattan, Professorial Fellow, University of Canberra

How to clear Victoria's backlog of elective surgeries after a 6-month slowdown? We need to rethink the system

ShutterstockWith the number of COVID-19 cases in Victoria continuing to trend downwards, Premier Daniel Andrews yesterday announced a phased restart of elective procedures in public and private hospit...

Stephen Duckett, Director, Health Program, Grattan Institute - avatar Stephen Duckett, Director, Health Program, Grattan Institute

Writers Wanted



News Company Media Core

Content & Technology Connecting Global Audiences

More Information - Less Opinion