Hit points
From LSWiki
Hit Points:
Your hit points represent how much abuse your body can take before you die. If the hit points of one of your limbs is reduced below 0, that limb will be disabled (killing you if it is your head); if it reaches -100% of its maximum maximum HP, it will be cut off. If your chest goes below 0 hp, you will begin bleeding to death and will die when your hit points drop below the -25% mark.
Hit points come back naturally, and regenerate faster when you are drunk. The more severe your wounds are, the more taxed your body is and so the more slowly you will heal. Many items and activities help healing as well.
