Health perk bugged?

Platform:
PC

Steps To Reproduce:
Buy the health perk that boosts your health by 10/20/30%.

Images / Videos:
None.

Host or Client:
Host.

Players in your game:
1, me.

Specifications:
N/A.

I got the health perk, all three tiers, and my character still only has 100 HP. I would expect to have more, is this a bug, or is it effectively armor that makes me take less damage resulting in more EHP?

– Lana