If you become wounded by a weapon you will start to bleed. Your bleed rate determines how much blood you lose each second.
Different weapons inflict different bleed rates, you can read more about the effects of weapons on the Melee Weapons and Firearms pages.
If you are bleeding, it will be displayed on the right of your character in the inventory screen. The text colour indicates the speed of the bleeding with red being the fastest.
Every time you are shot, hit, driven into or land a long fall, a wound will be inflicted to you. You can view how many wounds you have in the inventory screen.
Wounds affect your ability to perform in combat. If you have a lot of wounds then you are more likely to get knocked unconscious when another wound is inflicted on you. You can patch wounds up with a Doctor's Bag.
When you take damage, you have a chance to be knocked unconscious. This chance depends on how much blood you have, whether you are bleeding or not and how many wounds you have.
Random unconsciousness can happen when your blood drops below 40%. The nearer your health gets to 0% the more chance will increase.
Unconsciousness can be prevented by taking Adrenaline or Painkillers. A player can also revive you by using an Adrenaline shot on you while unconscious.
When unconcious other players can Disarm you by pressing Interact Key (Default F/Enter) while standing next to you.
When you are not bleeding, your blood regenerates automatically. You can speed this up by using Adrenaline or Morphine.
The three main medical items will aid you in getting healthy again:
Bandage: Slows or stops bleeding (depending on the severity of the wound).
Medkit: Same as a bandage, will also give you Painkillers.
Doctor's Bag: Stops bleeding completely, heals 1 wound, gives you Painkillers and Morphine.