How to permanently increase your health bar and posture

You’ll start off with a miniscule health (vitality) gauge. You can see it in the lower left corner of the screen. Obviously, having more health is essential for surviving longer by allowing you to take more damage before you can even heal. Your posture can only be seen when you block enemy attacks. The more posture you have, the more attacks you can endure.

You can permanently increase your vitality and posture by finding Prayer Beads. These items are dropped by mini-bosses or found as loot in different locations. Once you have four prayer beads, commune with a Sculptor’s Idol and select the option to Enhance Physical Attributes. The prayer beads will be combined to a Prayer Necklace, which will be added to your key items.

From hereon, you have to collect a new set of prayer beads again to increase your HP and posture further. Refer to this guide's dedicated section for finding Prayer Beads.