Red blood cells leak out of these blood vessels. These red blood cells that collect under your skin cause that bluish, purplish, reddish, or blackish mark. That's where black-and-blue marks get their ...

Australia's peak dermatology body is warning of innocuous skin markings that could premediate cancer. The Australasian College of Dermatologists (ACD) says dark marks under toe and fingernails could ...

Other signs of nail melanoma include darkened skin around the nail and cuticle, blood, pus and splits in ... away if you happen to notice a dark mark under your fingernail or any other suspicious ...

If the body is too hot, glands under the skin secrete sweat ... Some of this energy is released as heat to warm us up. Blood vessels supplying blood to the skin can swell or dilate - vasodilation.