Hyperlactation — breast milk oversupply — can have many causes, including:

• Breast-feeding mismanagement
• Too much of the milk production-stimulating hormone prolactin in your blood (hyperprolactinemia)
• A congenital predisposition
• Medications that increase milk production

Hyperlactation happens early in breast-feeding and causes full, leaking breasts that don't noticeably soften after a feeding. Breast pain, severe engorgement and painful milk letdowns are common.

Breast milk oversupply can also make breast-feeding difficult. The rush of milk during breast-feeding might be too forceful, causing an infant to choke and cough. Hyperlactation can cause infants to gain too much weight. Infants can also gain too little weight if they get too much carbohydrate-rich foremilk and not enough fat-rich hindmilk. Infants might be fussy at the start of feedings, have trouble maintaining a latch and act disinterested in feedings. They might also be gassy.

If you suspect hyperlactation, talk to a lactation consultant. He or she might recommend breast-feeding on one side per nursing session and offering that same breast for at least two hours, until the next full feeding. If your other breast becomes uncomfortably full, express it by hand or pump it for a few moments.

Positioning your baby so that gravity slows the flow of milk might help. Try leaning back during breast-feeding. Also, frequently burp your baby and allow him or her to come off the breast as needed.

Hyperlactation typically stops in a few weeks. If the problem continues, your health care provider might check to see if your thyroid is playing a role.