Blocked ducts
Milk blisters (blebs)
Recurring blocked ducts
Other causes of mastitis and how to prevent it
Treatments which are no longer recommended


You have a sore or tender breast, a change in color in an area of the breast, or feel a hard spot or small lump. What now? Could it be mastitis?
Whatever the reason for your sore breast:

  • Breastfeed as often as your baby wishes
  • Rest
  • Apply ice or cold packs to the tender area
  • If you are engorged, consider doing lymphatic drainage—a very gentle, light yet firm touch, with fingertips flat to the skin in the armpit area and upper chest. To see a demonstration of lymphatic drainage massage, you can watch this video
  • In consultation with your healthcare provider, consider using ibuprofen (Advil®, Nurofen®…) alternating with acetaminophen/paracetamol (Tylenol®, Panadol®…)

What breastfeeding experts used to think of as separate problems in the breast, such as mastitis, blocked ducts, milk blister “blebs,” and abscesses, are now suggested to be stages in the process of inflammation—the body’s response to a threat. The Academy of Breastfeeding Medicine (ABM) has revised their protocol explaining this: ABM Protocol #36.pdf: The Mastitis Spectrum. The information in this article is based on this ABM protocol1 and some tried and true LLL information.

Blocked Ducts

Milk flows through a system of microscopic-sized tubes—ducts—in your breasts, which are easily compressed. When more milk is produced than your baby drinks (for example, if you’re pumping in addition to breastfeeding), this can produce pressure which your body responds to as a threat. Inflammatory cells and fluids rush into the area to help repair the damage and fight off bacteria. The swelling that occurs from this inflammation presses on some of the ducts, which slows or blocks the milk from flowing well. The skin in this area may appear darker, redder, or pinker than usual. In darker skin, redness may not be as easily detected or may not be visible at all. It may feel warm to the touch. If this inflammation is not treated, the area can become more inflamed or infected. This can occur any time your breasts become overly full, Possible factors include:

  • You and your baby are separated for longer stretches than usual between feedings
  • Your baby starts sleeping longer at night
  • Your baby is teething, has a stuffy nose, or is otherwise feeling out of sorts and nursing less.

Treatment for what we know as blocked/clogged/plugged ducts and mastitis is similar. You may want to try the following ideas:

  • Consider yourself sick, and rest! Focus on caring for yourself, your breast, and your baby.
  • Apply cold or ice packs to the affected area.
  • Be aware that antibiotics may not be recommended right away. This is not an infection when it starts. Taking unnecessary antibiotics may encourage resistant strains of bacteria to thrive, and may make you more likely to have recurrent mastitis or an abscess in the future.
  • Make sure you are breastfeeding responsively to your baby (on cue) so that you don’t unintentionally go too long between feedings. You want a good match between your baby’s needs and the rate at which your breasts are producing milk. Read more about frequency of feeding in our FAQs.
  • Avoid excessive pumping. Pumping more than your baby needs may create too much milk, also known as hyperlactation.
  • Check to see that your baby or child is well-positioned and has a good latch or attachment. This helps the baby to take more of your milk.
  • Change positions when you feed your baby to increase your comfort. This video showing natural breastfeeding positions can be helpful.
  • If you wear a bra, make sure it is well-fitting, supportive, and not tight. Avoid clothing or straps that are tight on the breast, chest, and underarm area.

If you have frequent blocked ducts that are not helped by the above recommendations, taking a lecithin supplement may help. The supplement may be sunflower lecithin or soy lecithin, if you do not have sensitivities or allergies to soy or dairy. The evidence for this supplement is not strong. You can find more information about this in the ABM protocol.


A milk blister, or bleb, is usually a painful white dot on the nipple or areola. This is the result of inflammation or mastitis in the breast which sends inflammatory cells from the ducts down to the surface where they lodge in the nipple or areola area.

These are treated as any other condition in the mastitis spectrum. They do not always hurt and may resolve over several weeks. If you have a painful milk blister:

  • Apply ice or cold packs
  • Keep breastfeeding as your baby wishes
  • Follow the same recommendations as for blocked ducts

Avoid opening the blister yourself. It may bring some relief, but it also brings a risk of infection, more inflammation, and the possibility it will re-form. Avoid using soap or other cleansers on the nipple, as this can cause skin damage and pain.

If these suggestions don’t help, ask your healthcare professional for help. They may prescribe a steroid cream to help reduce inflammation, allowing better milk flow in that area.


Mastitis can occur when an area of blocked ducts continues to be compressed, or more generally, when your breasts become overly full, causing swelling and inflammation. This does not happen as the result of one delayed feeding, but rather is part of a process.

Chronic engorgement, over pumping or trying to “empty the breasts,” all increase the risk of mastitis. Areas of the breast where ducts are compressed may create opportunities for an imbalance in types of bacteria and result in an infection.

It is important for your baby to continue breastfeeding from the affected side to help prevent the inflammation from worsening and creating an abscess. It is a myth that it is unhealthy for your baby to breastfeed while you have mastitis. Mastitis is not contagious: there is no risk to your baby in continuing to breastfeed. Breastfeeding responsively can help to reduce the inflammation in your breast.

If you have mastitis, you can try all the recommendations in the section on blocked ducts, as well as the following plan. Many symptoms of inflammation will go away without antibiotics when you follow these guidelines.

Signs, Symptoms, and Treatment

If you:

  • Can feel a hard, sore lump in your breast
  • Feel achy, tired, or run down
  • Have a low-grade fever of less than 101°F (38.4℃)
  • Notice a change in the appearance of the skin on the affected breast. An area of red, pink, brown, or gray may be noticeable depending on your skin tone and which part of the breast is inflamed.  Some mothers have described a color change as triangular or “wedge” shaped on the skin. However, the absence of skin changes does not mean that mastitis is not present.


  • Rest as much as you can. Try resting in bed with your baby lying with you. Here are some LLL guidelines for safe bedsharing: sleep-safe-surface-checklist. Keep supplies such as nappies/diapers and wipes, toys, books, your phone, a container of water, and some snacks near you to minimize trips out of bed.
  • Keep applying cold packs or ice packs as often as you like to reduce inflammation and swelling.
  • Continue to feed your baby on cue, at least 8-12 times each 24 hours from both breasts. If you have a nursing toddler or older child, they may feed less frequently. If your baby refuses the sore side, you may need to express or pump some milk, just enough to soften the breast to the point it usually feels after a feeding.
  • To relieve engorgement, consider using lymphatic drainage, which is a very gentle, light yet firm touch, with fingertips flat to the skin in the armpit area and upper chest. This helps to move the fluid away from the ducts. Watch Lymphatic Massage for the Breast During Pregnancy and Lactation for a demonstration.
  • Ask your healthcare provider about using medications such as Ibuprofen (for example, Advil®, Nurofen®) to reduce inflammation alternating with acetaminophen/paracetamol (for example,Tylenol®, Panadol®) to help with pain.
  • Probiotics, taken by the mother, might help with mastitis.2 Two strains which were studied and found to be of possible help are Limosilactobacillus fermentum (also known as lactobacillus fermentum) or lactobacillus salivaris (also known as Ligilactobacillus salivarius).
    The authors of the ABM protocol state that more research is needed.

If you:

  • Do not feel any better, or feel worse after the first 24-48 hours
  • Develop a fever of 101°F (38.4℃) or more


  • Call your doctor or primary healthcare provider.
  • If antibiotic medication is prescribed, take it until the recommended course is completed, even if you feel better.
  • Continue to rest and drink plenty of fluids.
  • Continue to nurse. Hand express or pump (gently, try not to overdo this) if your baby is unwilling or unable to feed on the affected side. If unable to pump or feed from the affected breast, use ice to reduce inflammation until you are able to breastfeed or pump.
  • Discuss using therapeutic ultrasound (TUS) with your healthcare provider. If TUS is available in your area, it may be helpful to relieve edema (swelling and extra fluid in the breast) and reduce inflammation. Many areas do not have this technology available, and the evidence for TUS is not very strong.
  • If there is no improvement after 48 hours, you might ask your healthcare provider if culturing your milk would be appropriate or available. Milk cultures are not available in all areas and there is some debate about the value of them, as interpretation of the results is difficult.


An abscess is a swollen area of pus and bacteria walled off within the breast. This occurs in a small percentage of mastitis cases. It often appears as a very reddened or dusky area in a light skinned breast. In darker skin, redness may not be easily detected or may not be visible at all.

A well-defined area may feel hard and tender to the touch. It can seem to get better and then worsen, or your symptoms can worsen until the abscess needs to be drained.

In some cases, the abscess will open up and drain itself through the skin. If it needs to be drained, a physician (usually a radiologist or a breast surgeon) will either draw out the contents of the abscess with a needle aspiration, which may have to be performed several times, or by inserting a drain which will stay in place until the abscess has drained completely. Many experts believe that a drain should be done when aspiration of the abscess is first done, others believe it is necessary if a second aspiration of the abscess needs to be done. In certain cases, surgery under anesthesia is necessary. In addition, antibiotics will most likely be prescribed if you have an abscess. No matter how your abscess is taken care of, continued breastfeeding on the affected breast is valuable in decreasing inflammation.

It can be useful to discuss the options for your individual situation with a La Leche League Leader. If you need to have a breast imaging ultrasound, here is a reference for continuing to breastfeed after testing: lumps-and-breast-imaging.


In order to prevent future inflammatory problems, it is wise to be cautious of unusually long stretches between breastfeeds. Frequently changing your baby’s feeding positions, while ensuring a good latch may help with your comfort, putting pressure on different areas of the breast. Maintaining good general health through your diet and getting extra rest may help keep your breast from getting sore again. Examine your breasts gently each day. If you find an area of tenderness, make sure to rest, use cold packs, and continue breastfeeding or expressing your milk to decrease the inflammation.

Mastitis can recur for different reasons. When bacteria are resistant or not sensitive to the antibiotic which was prescribed or when the antibiotics are not continued for long enough, it can recur. It can also recur when nursing is not continued on the affected side; or when the initial cause of the mastitis is not corrected.

If mastitis recurs, ask your healthcare provider if you might be able to have a culture and sensitivity test done on your milk. This may be able to indicate what organism is causing the infection and what antibiotic will eliminate it.

Antibiotic-resistant bacteria are becoming much more common and are causing more serious infections, including in mastitis. Use of antibiotics, that do not attack the type of bacteria causing the infection, especially when used repeatedly, increases the risk of bacteria developing resistance to antibiotics. This can lead to an abscess.


There is some evidence that mastitis is more common in women who have recently taken antibiotics. Mothers who test positive for group B strep and those who have cesarean births are usually given antibiotics during their labor and delivery. This causes changes in the breast microbiome—the number and balance of microbes which live in healthy breast tissue. When the microbiome is changed in an adverse way, it is called “dysbiosis.”  Dysbiosis is one reason inflammation occurs.

Frequent pumping to build up a supply of milk in the freezer or to try to “empty the breasts” can be another cause of dysbiosis and inflammation from increased milk supply (hyperlactation).

Exclusively pumping can also affect the microbiome, since there is no feedback from saliva in the baby’s mouth to the nipple. Pump suction pressures may be higher or lower than the infant’s suction when feeding at the breast. Suction pressures that are too high can lead to breast and nipple trauma and inflammation, increasing the risk of mastitis. Suction pressures that are too low can lead to breast inflammation due to insufficient milk removal. Pumps do not remove milk as efficiently as a baby feeding well directly from the breast and may contribute to a bacterial imbalance in the ductal system. Taking care in selecting your pump flange size and checking regularly around the nipple and areola after pumping can help reduce these risks.

If you are exclusively expressing, you may find the following articles helpful:
Life as an Exclusive Expresser
Exclusively Expressing Breastmilk for Your Baby

Nipple shields, pacifiers and other artificial nipples can affect how babies suck. They can affect the microbiome of the ductal system and thereby initiate an inflammatory process. Of course these tools may be needed to help transition to direct breastfeeding or to soothe a baby when breastfeeding is not feasible. As always, we encourage you to do what is best for your family. If you are trying to minimize pump, shield, and pacifier usage, it can be useful to discuss this with an LLL Leader.

Some babies are reluctant to feed, have difficulties latching, or refuse the breast due to a nursing strike or other factors. Sudden changes in breastfeeding patterns may contribute to inflammation. Problems with inflammation commonly occur around the holidays or when you are entertaining company. At these times, feedings could be delayed more than usual due to your being busy.

Some bras and bathing suits, particularly those with underwires, may put too much pressure on areas of your breast. A heavy purse or bag with a strap that crosses your breast or baby carriers can cause pressure. Frequently changing which side you carry bags/purses on or how you wear your carriers, slings, and wraps may help.

Changing sleep positions throughout the night can help relieve pressure on the breasts. Wearing a stretchy sleep bra or camisole bra top may also help to take pressure off the breasts if you feel the need to wear a bra to sleep.

The shoulder strap of a seat belt can cause a sore breast, with a too tight strap applying pressure to your breast. Also, the pressure from the shoulder strap with a sudden stop may cause a sore breast. When taking long car trips, it is helpful to get out of the car to feed the baby periodically, which also removes pressure from the seat belt.

Certain injuries can result in sore breasts, such as being kicked or hit by an active toddler, or biting the breast. These may result in bruising and inflammation. Treat them with rest, cold or ice packs, and nurse per your baby/toddler’s cues.

Prior breast surgery, breast lumps, or injury to the breast can also hamper milk flow and increase the risk of inflammation.

Another common cause of mastitis is reducing or attempting to stop breastfeeding (weaning) suddenly or too quickly. You might develop mastitis when you return to work outside the home, for example. See our article Working and Breastfeeding for support in expressing your milk or to work feeding around separations.

Breastfeeding challenges can sometimes make you feel anxious or sad. Anxiety may lead to over-pumping to create a stash of breastmilk, potentially causing inflammation. If you are feeling this way, please talk to a La Leche League Leader, and reach out to your healthcare provider.

At times, mastitis is the result of difficulties with positioning and/or latch that impact how efficiently your baby takes milk from your breast. A La Leche League Leader can help you explore changes you can make to help prevent these conditions from recurring.
Get local support.

Treatments which are NO LONGER recommended

  • Heat to the breast, or soaking in warm water
  • Vigorous, deep massage, or squeezing to try to get rid of a clog
  • Dangling over baby for feeding to try to move a clog using gravity
  • Using a comb, vibrator, or electric toothbrush on the breast
  • Trying to “empty” the breast through extra pumping or breastfeeding which increases milk production
  • Using antibiotics right at the beginning of symptoms
  • Using Epsom salts in a Haakaa or similar silicone breast pump for nipple blebs
  • Using saline soaks, warm compresses, olive oil, castor oil, or other oils on the skin of the breast or nipple
  • Removing the skin or “popping” a bleb, which may allow infection to develop
  • Routine sterilization of pumps and household items is not necessary, although daily cleaning according to the manufacturer’s instructions is important to avoid infection from dirty pump parts.3 For more general information see this fact sheet.

Revised July 2023 by Dr. Justice Reilly, MBChB, IBCLC, and Susan Mocsny Thomas, RN


1. Some points in the protocol are controversial within the lactation community. We will note and comment on them.

2. As noted in the disclosure statements in the protocol, one of the authors (Dr. Juan Miguel Rodriguez) has been the PI (primary investigator) of research projects and clinical assays funded by Puleva/Biosearch Life (Granada, Spain) or Nutricia (Utrecht, The Netherlands), involving the characterization, safety, and efficacy of probiotic strains for the mastitis target. He and his research group have never received any payment or royalty related to the commercialization of probiotic strains.

3. If you do not have access to a safe water supply, you can clean pump parts with water boiled (at 212°F, 100°C) for at least 20 minutes.


If you would like to read more about the causes of mastitis, here is a good review: Interventions for the prevention of mastitis following childbirth | Cochrane

Since much of the information in the most recent ABM mastitis protocol is new, you may find it helpful to share it with your healthcare provider: ABM Protocol #36.pdf


  1. Mitchell, K. B., Johnson, H. M., Rodríguez, J. M., Eglash, A., Scherzinger, C., Zakarija-Grkovic, I., … & Academy of Breastfeeding Medicine, Clinical Protocol# 36: The Mastitis Spectrum, 2022, Breastfeeding Medicine, 17(5), 360-376, (accessed 7 February 2023)
  2. Mitchell, K. B., & Johnson, H. M., Breast pathology that contributes to dysfunction of human lactation: a spotlight on nipple blebs, 2020, Journal of Mammary Gland Biology and Neoplasia, 25(2), 79-83, (accessed 7 February 2023)
  3. Crepinsek, M. A., Taylor, E. A., Michener, K., & Stewart, F., Interventions for preventing mastitis after childbirth, 2020, Cochrane Database of Systematic Reviews, (9), (accessed 7 February 2023)
  4. Baeza, C, Paricio-Talayero, J.M., Pina, M and De Alba, C. , Letter re ‘Academy of Breastfeeding Medicine Clinical Protocol #36: The Mastitis Spectrum, Revised 2022’’ , Breastfeeding Medicine, 2022, Volume 17, Number 11, (accessed 7 February 2023)
  5. Mitchell et al, Response to Baeza et al re Academy of Breastfeeding Medicine Clinical Protocol #36: The Mastitis Spectrum, Revised 2022’’, Breastfeeding Medicine, 2022, Volume 17, Number 11, (accessed 7 February 2023)