You sacrifice some of your health to mend another creature's injuries. You take 4d8 necrotic damage, which can't be reduced in any way, and one creature of your choice that you can see within range regains this amount of hit points.

As part of casting this spell, you can expend up to three hit dice. If you do so, the target regains an additional 1d8 hit points for each hit dice you expend this way.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the damage you you take increases by 1d8 and the number of hit dice you can expend increases by one for each slot level above 3rd.