How long does it take to pass out from blood loss and bleed out?

[Darkmisc]

TL;DR Summary

I'm writing a story in which someone passes out from blood loss before they are found and saved. How long might a rescuer have before the victim dies?

Hi everyone

I'm writing a story in which someone passes out from blood loss before they are found and saved. How long might a rescuer have before the victim dies? I'm guessing there might be a lot of variables here, but I'm just looking for the longest possible realistic delay.

Also, if someone passes out from blood loss, would it be possible for them to have no recollection of the events leading up to their injury? Thanks

 

[256bits]

What to look for.
https://www.webmd.com/a-to-z-guides/hypovolemic-shock#1

 

[BillTre]

Someone could just freek out (psychologically) at the sight of blood and faint, with no real physiological problems, and stay alive a long time.

 

[Vanadium 50]

It's like a tire. The outcome depends on how fast the leak is.

 

[berkeman]

Summary:: I'm writing a story in which someone passes out from blood loss before they are found and saved. How long might a rescuer have before the victim dies?

I'm writing a story in which someone passes out from blood loss before they are found and saved. How long might a rescuer have before the victim dies? I'm guessing there might be a lot of variables here, but I'm just looking for the longest possible realistic delay.

Also, if someone passes out from blood loss, would it be possible for them to have no recollection of the events leading up to their injury?

If you want it to be a long time and include some memory loss, you could have them get cut somehow, see their bleeding and pass out from a Vasovagal reaction:

https://www.mayoclinic.org/diseases-conditions/vasovagal-syncope/symptoms-causes/syc-20350527

If they hit their head when they fall to the ground, that could result in a concussion or more serious brain injury, which could result in temporary or permanent memory loss.