Health

Summary
The player in Halo: Combat Evolved has a finite, non self-regenerating health which can be fully restored by picking up health-packs. Running completely out of health will result in death, but having lower health does not impede player actions. A player's health can only be reduced if his shields have failed.

In Halo 2, once the shields run out, the player also has a buffer of health. Unlike Halo: Combat Evolved, the health in Halo 2 regenerates after the shield. The amount of health left is not visible to the player.