The escape of blood from a ruptured vessel; it can be either external or internal. Blood from an artery is bright red in color and comes in spurts; that from a vein is dark red and comes in a steady flow. Aside from the obvious flow of blood from a wound or body orifice, massive hemorrhage can be detected by other signs, such as restlessness, cold and clammy skin, thirst, increased and thready pulse, rapid and shallow respirations, and a drop in blood pressure. If the hemorrhage continues unchecked, the patient may complain of visual disturbances, ringing in the ears, or extreme weakness.