ache, aching, affront, apple of discord, blow, bone of contention, bone to pick, casus belli, cramp, crow to pick, crow to pluck, cut, distress, dolor, exposed nerve, grief, grounds for war, hurt, injury, lesion, nasty blow, nerve ending, offense, pain, pang, passion, provocation, raw, raw nerve, red rag, rub, shock, soft spot, sore, sore point, sore spot, spasm, stress, stress of life, stroke, suffering, the quick, throes, ticklish issue, wound, wrench