Blood clotting is the body's natural response when the skin has been broken or a muscle has been injured. A clot is essentially blood that takes on a semi-solid or solid state and is not as fluid as usual. In the case of broken skin, the blood will congeal on the surface of the cut to protect the bloodstream from infection from outside sources. Dark bruises occur when the blood clots around internal tissues that have been injured.Usually a clot will dissipate on its own as the injury heals. Problems occur when blood clots do not fully liquefy and begin to travel through the veins and arteries. If a clot is large enough, it can become lodged in a smaller vein or artery and cause a blockage that will not allow blood to travel through that part of the cardiovascular system. The result is that any organs or bodily systems on the other side of the blockage are starved for the oxygen and nutrients they usually receive from the bloodstream.
