You have hormones to thank for the wondrous transformation in your breasts during and just after pregnancy. Whether or not you decide to breastfeed, you have to be impressed with the fact that your body is gearing up to produce milk. It's amazing, really. It also smarts like heck. That's a mild term for the full, hard, achy feeling that accompanies the first stages of lactation. If you're breastfeeding, those initial nursing sessions may be a big relief from the discomfort. If you're not, it will take a few weeks for your milk to dry up. Until it does, cold packs will provide some relief from the tenderness, reduce the swelling and speed the process along.