Bruises
A bruise, also known as a contusion is a relatively minor medical issue that all of us will encounter at one point or another in our lives, likely many times. It is often ignored but there are some first aid measures that can be taken to help minimize its impact.
A bruise on a persons arm.
In scientific terms, a bruise is known as a ecchymosis. It is caused when there is blunt trauma cause to the body and the muscle fibers and other connective tissue beneath the skin is crushed while leaving the skin intact. This can then cause blood in the ruptured capillaries near the skins surface to leak out, and since the skin has stayed intact is trapped and causes a dark coloring. Depending on the size and cause of the injury a bruise can take up to two weeks to totally heal.
A bruise will normally go through a number of color changes before being healed. It often starts as a reddish color, which in turn will change to blue, purple or black before lightening to green or yellow before it disappears from sight. These colours are caused by the gradual degradation of hemoglobin to biliverdin to bilirubin to hemosiderin, with hemoglobin producing a red-blue color, biliverdin a green color, bilirubin yellow color, and finally hemosiderin with the golden-brown color.