(a) Arterial hemorrhage may be recognized by rapid, spurting jets of red blood, occurring synchronous with the heart beat.
(b) Venous bleeding (from a vein) occurs as a steady even stream of dark blood, not affected by the heart beat.
(c) Capillary hemorrhage is in the form of a steady stream oozing from the raw surface of a tissue. The color is intermediary, as both arterial and venous capillaries contribute to it.
Nature’s Efforts to Control Hemorrhage. When an artery is severed, the inner and middle coats immediately retract and curl up within the lumen, partially closing up the cut end.
Blood has the property of clotting, if it comes in contact with anything but the natural endothelial lining of the vessels.
The curling in of the inner and middle coats retards the escaping stream and facilitates coagulation within the cut end of the vessel now formed by the outer coat alone. When the hemorrhage is severe, these processes are reinforced by an increased tendency to coagulate, and by a weakened heart action.
The Control of Hemorrhage. The object of treatment in every case is to check the flow of blood, and, though death from ordinary wounds is rare, yet the loss of much blood is weakening for a long time.
The principle on which we act in our efforts to permanently stop bleeding, depends on the power which the blood has of clotting, or as it is called, coagulating.
If by any means the blood can be made to “stand still” in a blood vessel at the point of injury, it will clot, thus forming a plug which prevents further escape.
In wounds involving only small veins or capillaries from which there is no distinct jet of blood (capillary hemorrhage), pressure of the thumb, a wad of sterile gauze intervening, will usually suffice in a few minutes. Gauze dipped in hot water applied to such wounds, also at times effects a stoppage of such bleeding. Often only tight bandaging is necessary.