The Blood Blister is a kind of blister formation which takes place when the subdermal tissues and blood vessels get extremely damaged without the skin getting pierced in some way or the other. This blister looks like a pool of lymph and it is entirely made of blood and other kinds of nasty fluid contents. If the blister gets punctured in any way then a dark red fluid oozes from the place. At times the blister can be quite painful when caused by an external object.The Blood Blister can to a great extent affect the hands and the feet. Thus, it is important to seek for the right treatment in this case.