Here's how it will work:
When you get knocked unconscious from being bludgeoned by something, you must wait for about 1-3 minutes (Based on the weapon and location). This can be increased by 30 seconds every time your hit. 5-7 hits will kill you (Depending on the weapon).
Once you regain consciousness, if you get knocked out again in a 1 minute time frame, you have a chance of dieing while unconscious. (25% chance every 30 seconds)
The chance increases the more you are knocked out in that time frame, until you die from severe brain trauma.
When you are shot by a gun or hit by any weapon, there is a 20% of staggering.