Bleeding, or haemorrhage , poses a threat by causing both the volume and the pressure of the blood within the body to decrease through blood loss. Serious wounds involve damage to blood vessels. As arteries carry oxygenated blood from the heart, damage to a vessel is characterised by bright red blood which 'spurts' with each heartbeat. Damage to veins appears as a darker red flow. Capillary damage is associated with wounds close to the skin and is of a bright red 'ooze' from below the surface.
Abrasion is a wound where the skin layers have been scraped off.
Puncture wounds are perforations, and may be due to anything from a corkscrew to a bullet. Amputation is the loss of a digit or limb by trauma. Constrictive bandages are a measure of last resort, and should only be used in a life threatening situation where all else fails. Freezing will kill tissue. If bleeding continues and seeps through the bandage and padding, remove and replace these, leaving the initial dressing in place.