What’s a milk blister, or bleb?

Reviewed by Leah DeShay

Chances are, you never heard of a milk blister, or bleb, before you started breastfeeding. A bleb is basically a blister that can crop up when your milk gets backed up behind a blocked milk duct opening. You might notice it in the form of a tiny white spot at or near the very tip of your nipple.

What it is

A bleb, commonly called a milk blister, can arise when your milk thickens and gets backed up. It appears as a raised section of skin with milk beneath it either on or near your nipple. When this happens, a small white or yellow spot resembling a whitehead can appear.

When it can occur

Blebs most often form in the early weeks and months of nursing, and tend to be linked to improper latching. However, they can happen at any point during your breastfeeding journey, even as you attempt to wean from breastfeeding, and can take a week to clear up.

What causes it

Milk blebs can form for multiple reasons, the most common being an ill-fitting pump flange or a poor latch. When your baby is not latching on to your nipple properly, your breasts might not fully drain, and your milk can build up in your breast. Oversupply can have a similar effect, with more milk being produced than expressed. Bras that restrict your ducts or irritate your breasts are another culprit. If you have recurrent milk blisters, get in touch with your provider.

What to do

Try to continue breastfeeding normally, especially on the nipple where the bleb is located. If the bleb is painful, try the following interventions:

  • See a lactation consultant to ensure that your baby is latching properly.
  • Place a warm, clean cloth over the bleb, and massage it before expressing milk.
  • Hand-express some milk prior to feeding to try to clear the blockage.
  • Breastfeed or pump more often to maintain supply while preventing engorgement or mastitis.
  • Air out your breasts—bacteria thrive in tight, damp areas—by going topless or braless when you can, and wash your tops and bras regularly.
  • If the bleb is protruding from the skin, you can try to gently lift it with clean fingers yourself (much like you might with a callous), but know that there are risks, such as introducing more bacteria. Ideally, just leave it alone, because playing with it can make it worse or recurrent.
When to get help

Contact your provider if:

  • After a few days, the bleb continues to be painful. Your provider may be able to break the skin and release the blockage with a sterile needle, or prescribe an antibacterial cream.
  • You develop a fever or other flu-like symptoms, which could indicate the development of mastitis. (Blebs can also lead to clogged ducts.)

Additional resources

What’s engorgement?

Breast engorgement is a common but uncomfortable condition when the breasts become swollen, tight, and sometimes warm to the touch.

What are sore nipples?

Sore and sometimes painful nipples are so common at the start of breastfeeding that you can almost expect some discomfort.

What’s mastitis?

Mastitis is a noncommunicable condition marked by painful inflammation of the breast tissue in one or both breasts.