In Junk Jack, health is measured by hearts in the top left of the screen. You can lose these hearts by being attacked by Mobs or from falling from a distance of three blocks or higher. These hearts can be restored using the various food items in the game. Sleeping in a bed will completely heal all 5 hearts.
- The most hearts you can have is 5.
- The smallest increment you can lose hearts is 1/4 heart.
- The smallest increment you can heal yourself is 1/4 heart.