Why do we call it blue-black? The literal description of what it is. A bruise is indeed blue-black in colour at a glance. That's why we have the phrase "black eye" too.
On further reading, this is what it says further about a bruise.
* When you first get a bruise, it's kind of reddish as the blood appears under the skin.
* Within 1 or 2 days, the hemoglobin (an iron-containing substance that carries oxygen) in the blood changes and your bruise turns bluish-purple or even blackish.
* After 5 to 10 days, the bruise turns greenish or yellowish.
* Then, after 10 or 14 days, it turns yellowish-brown or light brown.
Yesterday, I got shot by a professional paint ball shooter and I am still alive. :P
I was in Johnson & Johnson Motor Hunt with my friends. In one of the challenges, we were supposed to grab a flag before any of us got shot. Smart of me to get shot in my thigh...
Didn't I learn a lesson the last time I got shot on the back at close range!?! The bruise and mark took more than a month to recover! I still remember it was a guy who shot me! Meanie! But I don't think I can pick him out from a mug shot now. :(
Yesterday the bruise was reddish in colour. Today it has morphed into the deep bluish-purple colour. Its slightly bigger than a fifty cents coin. I dilligently rubbed the greenish Zam-Buk ointment into the bruise.
This got me thinking, why do people use hard boiled egg to reduced the swelling of a bruise?
Hard boil an egg and place it in a piece of cheesecloth.
Gather the edges together and tie a knot or secure it with a rubber band.
Break the egg, remove the shell and all, and apply the cheesecloth bag to a bruise. The egg will help heal the bruise as the warmth reduces the pain and swelling.
On further surfing online, I found there are many more remedies recommended by our online fellow friends.
This remedy works on bruises because it constricts the blood vessels, and so less blood spills into the tissues around the injury. If using an ice pack, make sure it is wrapped in a towel to avoid frostbite. Better yet is to use cold water. Ice or chill your bruise for no more than 15 minutes. Allow the skin to warm for 10 minutes, then you can chill again.
And many more remedies can be found online like this site.
However, so far while growing up and falling all over, I have only tried these two remedies.
Maybe the next time, I should test out the other remedies recommended here. Then I can have a cocktail of apple cider vinegar poured into a bowl of ice and add in with a hardboiled egg, a dab of melted butter, crushed a few tablets of vitamin C and add in a few slices of raw pork fat for the Bruise Cure! :p
(No insult intended. Just an exaggeration of trying all remedies at one go!)