Mastitis Symptoms and Treatment

Mastitis is the name for an inflammation within the breast. Symptoms of mastitis include a feeling of soreness, pain, heat and swelling (inflammation) in the breast. You may see red flushing or pink areas of skin above an engorged area, feel a tender spot or a sore lump inside your breast, and you may feel achey and run down or even shivery with flu-like symptoms. There may or may not be a bacterial infection, if there isn’t an infection, mastitis symptoms often clear on their own after a day or two of careful treatment. This article looks at the causes of mastitis in lactation, how to prevent it and what to do if you have mastitis.

Definition and Diagnosis
The usual clinical definition of mastitis is a tender, hot, swollen, wedge-shaped area of breast associated with temperature of 38.5C (101.3F) or greater, chills, flu-like aching, and systemic illness. However, mastitis literally means, and is defined herein, as an inflammation of the breast; this inflammation may or may not involve a bacterial infection. Redness, pain, and heat may all be present when an area of the breast is engorged or ‘‘blocked’’/‘‘plugged,’’ but an infection is not necessarily present. There appears to be a continuum from engorgement to non infective mastitis to infective mastitis to breast abscess.

What causes mastitis?

Mastitis is the body’s reaction to a build up of breast milk sitting in the breast (milk stasis). Milk can build up in the breast due to infrequent feeds, a blocked duct or poor breast drainage, leading to an over full breast (engorgement). Typically this happens if your baby isn’t feeding as well as they could and they are not emptying the breast thoroughly. Sometimes poor breast drainage can be caused by tight clothing such as a tight bra pressing on the glandular tissue in the breast and some mothers notice they can get mastitis when they have tried to do too much.

Typical causes of mastitis are nipple damage that lets bacteria in, milk that isn’t removed regularly and well, and a body that’s just generally run down. That usually translates to nipple trauma from a baby who isn’t latching well, infrequent or inefficient breast emptying, something that routinely presses on certain milk ducts (such as poorly fitting or underwire bra, or a backpack), or trying to do too much on too little sleep with too little food (“holiday mastitis” is common).

Preventing mastitis

Emptying your breasts by frequent breastfeeding, hand expressing or pumping to comfort at the first sign of engorgement can prevent mastitis. Sore, cracked nipples may increase the risk of a breast infection so washing damaged nipples daily with a mild soap is another preventative measure—see What Can I Put on Sore Nipples?

Mastitis treatment

A mastitis treatment plan includes:

  • Empty the breast—continue to breastfeed as often as you can to empty the affected breast while not forgetting the other breast. If your baby can’t do this by breastfeeding, or if it is too painful, you will need to hand express or pump to remove milk until you feel comfortable again.
  • Moderate warmth on the breast can help trigger the let down before you breastfeed or express.
  • Gentle massage of the lumpy areas can get milk flowing or see Engorgement Relief When Milk Won’t Flow if you are struggling to get milk flowing.
  • Check latch and positioning— see  Breastfeeding Positions for NewbornsBreastfeeding Videos and Latching Tips or seek help from your IBCLC lactation consultant or breastfeeding specialist to get your baby’s latch just right—both to aid a speedy recovery and to prevent mastitis coming back again.
  • Cold ice packs (e.g. frozen peas or crushed ice in a damp cloth) placed against the sore, red and engorged areas for up to 20 minutes at a time, will help reduce breast inflammation between feeds. Many mothers have found that chilled cabbage leaves in the bra also soothe the area.
  • Compatible pain-killers or anti-inflammatory medication will help with the pain and inflammation.
  • Rest and look after yourself, and remember to eat and drink!
  • Check with your health care professional if there is no improvement after 24 hours.

When should I see my doctor?

If you are not starting to feel better after 12-24 hours of treatment and if you have any of the symptoms in the following excerpt, contact your health care professional for advice.

When you have mastitis… Talk to your doctor about starting antibiotics immediately if:

  • Mastitis is in both breasts.
  • Baby is less than 2 weeks old, or you have recently been in the hospital.
  • You have broken skin on the nipple with obvious signs of infection.
  • Blood/pus is present in milk.
  • Red streaking is present.
  • Your temperature increases suddenly.
  • Symptoms are sudden and severe.

What medication can I take?

Ibuprofen and paracetamol are compatible with breastfeeding1. And your health care professional will be able to prescribe compatible antibiotics for a bacterial infection if they are needed.

Analgesia [Painkillers]. Analgesia may help with the let-down reflex and should be encouraged. An anti-inflammatory agent such as ibuprofen may be more effective in reducing the inflammatory symptoms than a simple analgesic like paracetamol/ acetaminophen. Ibuprofen is not detected in breast milk following doses up to 1.6 g/day and is regarded as compatible with breastfeeding.

Antibiotics. If symptoms of mastitis are mild and have been present for less than 24 hours, conservative management (effective milk removal and supportive measures) may be sufficient. If symptoms are not improving within 12–24 hours or if the woman is acutely ill, antibiotics should be started.

Treating a blocked duct

Treatments for a blocked duct or a plugged duct are much the same as for mastitis i.e. continue breastfeeding, take pain relieving and anti inflammatory medication as needed and try compressing or gently massaging the area of the blocked duct while feeding. A warm compress or heating pad over the area prior to a feed may help release it. See Blocked Milk Ducts for more information.

Engorgement due to your milk coming in

Bear in mind engorgement due to your milk coming in around day three or any time in the first couple of weeks, can include blood and tissue fluids rushing to the area. Too much heat on the breast at this time could cause blood vessels to widen (dilate) and bring even more fluid to the party. For more information about preventing engorgement and how to deal with it see Engorged Breasts.

When baby can’t latch

Sometimes engorgement behind the nipple can change the nipple shape making it difficult for your baby to latch and almost having the effect of someone stepping on a hose, stopping the flow of liquid. If you’re struggling to express any milk at all or your baby can’t seem to latch have a look at Engorgement Relief When Milk Won’t Flow for ideas to help you.

White spot on my nipple?

If you have a white spot on your nipple alongside symptoms of mastitis, see the section about milk blisters or blebs in Blisters on Nipples for more information.

I Keep Getting Mastitis or Blocked Ducts

If you keep getting episodes of mastitis or blocked ducts see Blocked Milk Duct for a discussion of risk factors and contact your IBCLC lactation consultant to check your positioning and latch and to help you brainstorm other likely causes.

Is it Safe to Continue Breastfeeding my Baby if I Have Infection Based Mastitis?

Yes. Antibodies in your milk will help protect your baby from any infection. Your milk may taste slightly salty when you have mastitis but this doesn’t usually pose a problem to your baby.

There is no evidence of risk to the healthy, term infant of continuing breastfeeding from a mother with mastitis. Women who are unable to continue breastfeeding should express the milk from breast by hand or pump, as sudden cessation of breastfeeding leads to a greater risk of abscess development than continuing to feed.

If the mother has symptoms of a bacterial infection, encourage her to contact her healthcare provider to evaluate whether medication is needed. Whether or not a mother needs antibiotics, breastfeeding can and should continue. Sudden weaning puts a mother at risk of her mastitis worsening into a breast abscess, a much more serious condition.

Most cases of infection based mastitis are caused by Staphylococcus aureus bacteria (staph). For more information about breastfeeding and staph infections see Staph, MRSA and Breastfeeding.

MRSA and breastfeeding

Methicillin-resistant Staphylococcus aureus (MRSA) is a bacteria that is resistant to certain antibiotics. When a mother is colonised with MRSA and her baby is healthy and full term most breastfeeding resources recommend continuing to breastfeed while the mother starts antibiotic treatment. Author and lactation consultant Nancy Mohrbacher IBCLC explains that breastfeeding can continue, unless a baby is poorly or premature, because the baby has already been exposed to the infection before diagnosis:

If a mother develops an MRSA infection, the baby has already been exposed to it before her symptoms became obvious, so there is no reason to stop breastfeeding unless the baby is compromised (ill or preterm). If the baby’s health is fragile, the mother’s milk could be pasteurised before feeding it to him (Gastelum, Dassey, Mascola, & Yasuda, 2005: Kim et al.,2007), or if that is not an option, her milk may need to be discarded until it is clear of infection.

It is important to take sensible hygiene precautions such as covering any areas of MRSA infected skin, washing yours and your baby’s hands, sterilising pump parts and nipple shields, and using disposable breast pads.  If there is an active MRSA infection on the breast, particularly when very close to the nipple, advice varies as to whether an interruption of breastfeeding for 24-48 hours may be needed see Staph, MRSA and Breastfeeding for further information and consult with your health care professionals.


Mastitis is the name for an inflammation in the breast. During breastfeeding, mastitis is the body’s reaction to a build of breast milk that is not getting drained from the breast. Mastitis can be very painful and a mother may have general symptoms similar to flu (shivers, temperature, feeling unwell) as well as a very painful sore breast (or two). At the first sign of engorgement—breastfeeding, pumping, or hand expressing until the breast is comfortable again can help to avoid mastitis. Sometimes mastitis is associated with a bacterial breast infection and requires antibiotics. There are several antibiotics compatible with breastfeeding—it is important not to stop breastfeeding or stop frequent milk removal during an episode of mastitis or it could develop into a breast abscess. If mastitis keeps coming back, check your baby’s latch and positioning with your breastfeeding specialist or IBCLC lactation consultant.

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