Embolism

When you cast this spell, your current hit points are reduced by an amount equal to the spell's level.

You manipulate the flow of blood within a creature's body, causing an aneurysm to form and eventually rupture. Choose a creature that is not a Construct and has blood. The target must make a Constitution saving throw. On a success, the spell has no effect. On a failure, the target gains 2 levels of exhaustion, and is incapacitated as long as they have a level of exhaustion. An affected creature gains an additional level of exhaustion at the end of every hour until death.

Only a Greater Restoration spell or similar magic can reduce the target's exhaustion while under the effects of this spell. Once the target's exhaustion level is reduced to 0, the effects of this spell end.