Losing health when I cast spells

Iam losing health when I cast spells. I don't have any gear on that hurts me. I do have a weapon that gets 14 life per kill. But I will be by myself with no enemies nearby and cast ball lightning then lightning warp and I will lose health and I don't know why.

It could be skills or skill points possibly? My current build my health and mana are tied together so casting or taking damage I lose health.