4e had a specific status called "bloodied" that creatures gained when they dropped below half HP
This is in 5e, below half health an enemy or NPC is described as showing injury, below 25% is described as seriously injured, and below 10% is described as near death.
This is in 5e, below half health an enemy or NPC is described as showing injury, below 25% is described as seriously injured, and below 10% is described as near death.