I have some really sore nipples. Not cracked, bleeding or anything like that...just sore after pumping and the initial start of pumping. Which of course then carries over to actual nursing because I have pumped 2x a day. I found this on LLLI:
Choose a pump with different sized flanges or breast shields
Some pumps have the option of different sized breast shields or flanges. A well fitting flange will allow for comfortable pumping and a good flow of milk. A mother should be comfort- able both while pumping and afterward (this is where I'm different, I'm sore afterwards and in the very start). While pumping, she should see her nipple moving easily in the tunnel of the flange, pulling her areola slightly with it. Her nipple should not rub against the sidewalls of the flange (Jones 2009).
I fit that description. Which tells me that it is not an issue of fitting properly. Are my nipples sore just because of pumping or is there something I should change about my pump or pumping?
Think sore muscles after working out.
Re: Sore nipples
When I started pumping after I went back to work with DD my nipples and eventually breasts got SO SORE and I had no idea why. I was using the Medela PISA that I'd used with DS - with no problems. I spent hours online reading about "properly fitting breast shields" forever and couldn't decide whether or not I needed smaller ones, bigger ones, etc. I ended up meeting with a Lactation Consultant who evaluated my pump (it was fine), the fit of my shields (they looked fine) and we concluded that perhaps I had a little Reynaud's (I have it in my toes) but also probably had the pump turned up a little too high. While I was in the office she hooked me up to a Medela Symphony and it was very comfortable. I ended up renting one and still have it. BUT, over my many months of pumping have still had some bouts of irritation that have cleared up with the following tweaks:
1) a larger shield (I would say my nipples are average-sized but my left is bigger than the right. I use a 30mm shield on my left, and a 27mm on my right)
2) using a little olive oil on them before puming (to lubricate)
I don't know if I'm being helpful or not, but you might want to experiment with some different sized shields, maybe turn down the pump if you use a high setting, and try a little olive oil. Just some thoughts...
Re: Sore nipples
Probably the suction is too high.
Is nursing painful in an of itself, or just as an after-effect of pumping? The times you don't pump, does it still hurt to nurse? Possibly it could be the reverse, that something is going on with your baby's mouth that's causing you pain/damage (not to the cracking/bleeding stage), and that pain is carrying over to the pump?
Another consideration is thrush?
How old is your baby? Could you possibly be pregnant??
You could also try softening the breast/nipple before pumping by massaging the breast and then hand-expressing a little milk before starting the pumping. Breastmilk would also lubricate the area and possibly help with this??