Bleeding is a status most often given to a unit by a unit belonging to the opponent. The status is recognisable as a red banner under the unit’s power. The number inside the banner indicates how many more procs the status has before it disappears.
It is important to note that Bleeding and Vitality are mutually exclusive statuses that cancel each other out. If a unit with 5 Bleeding is given 1 Vitality, it will be left with 4 Bleeding. Similarly if a unit has 3 Vitality and is given 6 Bleeding, it will be left with 3 Bleeding.