Health is the player-character's physical wellbeing. If a player's health runs out, their character dies. Lowered health does not affect a player-character's stamina, movement speed, or other physical attributes.
Halo: Combat Evolved
- Main article: Halo: Combat Evolved
Players in Halo: Combat Evolved have a limited, non-regenerating supply of health. A player's health can only be reduced if their shields are down. Health can only be restored by picking up health kits.
Health is shown on the heads-up display using a horizontal bar broken into eight segments. The health bar and the health symbol (denoted by a cross) change color to represent the approximate amount of health a player has left. The bar turns yellow when half or more of a player's health has been depleted. When only two segments remain on the bar, it will turn red. In addition, when only one or two segments remain, the sound of a beating heart can be heard.
- Main article: Halo 2
Health in Halo 2 is not shown on the HUD. It recharges fully over time at a slightly slower pace than the shields.
- Main article: Halo 3
In Halo 3, players have 115 hit points: 45 health points and 70 shield points. If a player avoids taking health damage for ten seconds, his health will regenerate at a rate of nine points per second.
Halo 3: ODST
- Main article: Halo 3: ODST
In Halo 3: ODST, players once again have a health bar that is shown on the HUD. A player's health in ODST can only be damaged after their stamina is depleted. Because players play as ODSTs and are therefore weaker than Spartans, health in this game is depleted much faster than in previous games. Health can only be restored using health kits.
- Main article: Halo: Reach
Spartans in Halo: Reach have 45 health points and limited regeneration. If a player avoids taking health damage for four seconds, his health begins regenerating at a rate of 2 health points per second up to a maximum of 15, 30, or 45 health points, whichever is reached first. If a Spartan's health is brought down to or below 30 points, the remaining health can only be restored by picking up a health kit or by entering a Drop Shield. Elites cannot use health kits, but their health regenerates completely, though more slowly than a Spartan's.
- Main article: Halo 4
Halo 4 uses the same shield and health system as Halo 2 and Halo 3. The health regeneration delay and rate are unknown.
Halo: Spartan Assault
- Main article: Halo: Spartan Assault
Halo: Spartan Assault uses the same shield and health system as Halo 2, Halo 3, and Halo 4. The health regeneration delay and rate are unknown.
Halo 5: Guardians
- Main article: Halo 5: Guardians
Halo 5: Guardians's shield and health systems are the same as in Halo 4. This time, though, the HUD now has a visible health bar divided into four segments. Any lost health is regenerated at a slower pace than the shields, as with previous games. The health regeneration delay is 3 seconds after being hurt.
When a character's shields have been reduced to 0%, he/she will emit different pain grunts/sounds compared to when having shields. In the campaign, should a character's health reach 0%, he/she will be rendered unable to continue unless revived in time by an ally (denoted by a square-shaped health bar that constantly runs out).