Below we describe how to increase the maximum stock of health points and and level up your Vitality (and Posture).
In Sekiro, the wolf has two main characteristics - Vitality (which includes Posture) and Attack Power. And to increase the first you need to collect four Prayer Beads, the second - memories.
After you destroy the more powerful opponents in the game, who usually have "two health points" (that is, you need to put two deadly blows or two times to completely destroy the health scale), Prayer Beads will fall out. Some of them can be found in the game world - in treasure chests hidden in hard-to-reach places.
After collecting four Prayer Beads, visit any Sculptor’s idol to activate the item “Enhance Physical Attributes”. Four beads will turn into a Prayer Necklace. This will increase 1-point boost to your Vitality (and Posture).