What do i do for lump in breast after a car wreck?

Wait and watch: You probably have a big hematoma (bruise) where your seatbelt went across your breast. You may not see a bruise, but it can be deep within the breast. It takes time for your body to heal this, so it may be a month or two before you notice it getting better. Use ice packs. If it's getting worse, not better, see a doctor. Rarely the area can keep bleeding inside your breast, requiring surgery.