Your blood is the most important factor of the Game. It is the meter in stats that decides if you are dead or not.

If you are an Alien your blood will heal over an amount of time.

Predators and Marines have to go to a User Shop and buy some healing items to heal themselves.

Tip: You can buy a mass clan heal item in the clan store that will heal your whole clan at the cost of your adrenaline levels.

Blood can be refilled only with special items made by crafters. See Healing.

Once your blood runs out from being attacked you will die and lose some money, CPUs,Resources and Experience. And your blood will regenerate back to full along with all the other stats. You will also loose Max Blood and Max Adrenaline when you die.

Some items cause bleeding over time. See bleeding

If you find yourself with negative blood, you will not be able to attack or play the game normally until you heal.