We have all seen movies where someone takes a bullet or a knife wound and starts to lose blood. Depending on the level of realism in the movie that person seems to be able to stay there bleeding for a few hours or a few days before they die. In reality, how much blood is life-threatening to lose and how much is not a big deal? Read on to find out.
Blood accounts for around 8% of a person’s body weight. The average man has around 12 pints of blood running through his system at any one time with the average woman slightly lower at 9 pints.
When we donate blood, around 1 pint is usually taken from the body. This is approximately 10% of our total blood level and is seen as a safe amount. It only takes the body 24 hours to replace lost plasma cells in the body. However, it takes 4 to 6 weeks to replace the lost red blood cells, rich in iron. When a person donates blood it can take up to 12 weeks for their body to return to full normality. With this in mind, while donating blood is totally safe and highly recommended you should try to only donate ever 8 to 10 weeks to ensure your body is fully functioning.
While 10% blood loss is deemed safe, it will only take 20% for the body to go into early forms of shock. If the body loses ⅕ of total blood there is no longer enough oxygen getting into the different parts of the body. If this blood loss worsens or is left unattended for a long period it can result in brain damage or death.
The first sign of someone losing too much blood is if they start to feel numbness or go pale. The body is reacting to the extreme blood loss and is prioritizing vital organs, instead of skin and hands and feet.
So If you ever see a movie where someone survives serious blood loss of a long period than feel free to point out to the rest of the room how unrealistic it is. More seriously, if you do ever find someone losing a lot of blood. Call an ambulance. Raise the wound above the heart so blood is no longer rushing to that area. Apply pressure to the wound and wait for help.