Health is what keeps you alive in Paranautical Activity, when the counter hits zero you are dead. The number of filled Health containers the player spawns ranges from 3 to 9, based on the chosen class. If the player is hit they may recover from the damage by picking up Health. Additionally, the player can increase their maximum number of Health containers by obtaining items such as Dobee's Blubbler or Spinach.
There is currently a bug in which the player will pick up a Health container and a ghost image of it will float around the player. This is entirely a graphical glitch and can be fixed either through time or by going to the next floor.