Withering

You grow pale and sickly as your vitality is drained away.
Withering is a worse form of Atrophy that is potentially permanent.
Each point reduces all incoming healing by 2. 
When you can no longer heal from your hit dice (including Strength Bonus), you become Nauseated and are Vulnerable to all damage. 

Recovery

When you complete a Night's Rest, you can attempt an Exertion Save with DC 10 + Withering. If you succeed, one point of Withering is healed. If you fail, remove one point of Withering, but reduce your Hit Dice by one step (this does not change your Max HP retroactively).
If your Hit Dice are reduced below d1, they become Corrupted Hit Dice.

Type

Magical