Here's my half baked theory about nipple pain/sensitivity. Nipples are exquisitely sensitive because they have a high concentration of nerve endings. Other organs with similar innervation are the glans penis and clitoris. The reason is to achive certain important neurologically mediated physiologic reflexes eg, ejaculation, milk ejection reflex etc. When the baby first starts sucking on the nipples, the stimuation of all those nerve endings can be perceived as pain. However, beacuse of some physiologic modulation, probably at the spinal or subcortical level, the pain disappears after a few minutes. Just like every person has a different pain threshold, every woman will have a different level of nipple sensitivity. I do belive that toughening of the nipples plays a part. My own experience was that of toe curling pain when my first born daughter,(who was a nursing champ from the minute she was born) first latched on. With my 3rd baby it just felt like licking. I never had MERs as whopping as I did with my first baby. Vaishali Kute, MD IBCLC hopeful Atlanta GA *********************************************** To temporarily stop your subscription: set lactnet nomail To start it again: set lactnet mail (or digest) To unsubscribe: unsubscribe lactnet All commands go to [log in to unmask] The LACTNET mailing list is powered by L-Soft's renowned LISTSERV(R) list management software together with L-Soft's LSMTP(R) mailer for lightning fast mail delivery. For more information, go to: http://www.lsoft.com/LISTSERV-powered.html