Mastitis Symptoms and Treatment

What is mastitis?

Mastitis is an inflammation of the breast which can cause a collection of distinctive symptoms from a sore, painful breast to flu-like symptoms. Mastitis is the body’s reaction to a build up of breast milk sitting in the breast (milk stasis). If the pressure of milk in the breast gets too high—when breasts are over full or engorged—it is thought that some of the components of breast milk leak into the surrounding breast tissue causing inflammation. Mastitis is a relatively common condition affecting breastfeeding women.

This article

This article looks at the symptoms and causes of breastfeeding related mastitis, and how to prevent and treat it.

Symptoms of mastitis

The symptoms of mastitis can include:

  • Soreness, pain, heat and swelling (inflammation) in the breast
  • A sore lump or tender spot inside the breast
  • Areas of red or pink skin on the surface of the breast, may include red streaks or lines. Colour changes may not be visible on darker pigmented skin.
  • Flu-like symptoms such as feeling achey, shivery or run down, headache
  • Bacterial infection (may or may not be present)
  • Increased sodium levels in breast milk making it taste saltier
  • Usually affects one breast, rarely both breasts
  • Some mothers notice pumped breast milk can be lumpy or clumpy 1

Bacterial infection

Mastitis is not always associated with a bacterial infection. When there isn’t a bacterial infection, mastitis symptoms often clear on their own after a day or two of careful preventative treatment (see the “Mastitis action plan” below). If a bacterial infection is present, this is usually due to Staphylococcus aureus (staph). Where mastitis affects both breasts, the cause may be Streptococcus (Strep) 2. The US based Academy of Breastfeeding Medicine explains:

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?

Causes of mastitis typically include:

  • A baby who is not emptying the breast properly—causing engorgement or blocked ducts e.g. a baby with a shallow latch, or using a poorly fitted nipple shield.
  • A baby who is not emptying the breast often enough, perhaps due to scheduled feeds, use of a pacifier, separation of mother from baby for several hours, or the first time a baby sleeps through the night
  • A baby who is feeding less due to illness
  • Abrupt weaning
  • Anything pressing on the glandular tissue in the breast which could interfere with milk flow such as a tight bra or other clothing, the straps of a heavy bag or even mother’s sleeping position or a finger pressing firmly into the breast throughout a feed
  • A true oversupply of breast milk
  • A stressed mother who is trying to do too much or who is run down, poorly or not eating properly

Other risk factors include:

  • A history of mastitis 3
  • Sore, cracked nipples prior to the mastitis episode (Foxman et al, 2002)
  • Using nipple creams and gel pads 4 including using antifungal cream, either due to thrush or perceived thrush (Foxman et al, 2002).
  • Use of a manual breast pump during the same week as the mastitis episode (Foxman et al, 2002)
  • A mother who does a lot of vigorous exercise especially using the upper arms and chest 5

Preventing mastitis

Breastfeeding frequently with your baby in a deep, comfortable latch and hand expressing or pumping to comfort at the first sign of engorgement or a blocked duct can prevent mastitis. Breast compression and massage can also help to drain the breast thoroughly. For more information about preventing engorgement and how to deal with it see Engorged Breasts. 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 Treatments for Sore Nipples

Mastitis treatment

If you have mastitis it’s important to take action quickly to keep milk flowing, reduce engorgement and keep comfortable—see the ideas in the action plan below. If you don’t see any improvement after 12-24 hours, check with your doctor in case antibiotics may be needed.

Mastitis action plan

  • Empty the breast—continue to breastfeed as often as you can to empty the affected breast of milk—while not forgetting the other breast must also still be drained regularly. If your baby can’t empty the breast by breastfeeding, or if it is too painful to breastfeed, you will need to hand express or pump to remove enough milk until you feel comfortable again.
  • Moderate warmth on the breast can help trigger the let down before you breastfeed or express. Warmth can also help with pain relief 6.
  • Gentle massage of the lumpy areas combined with hand expression can get milk flowing and see Engorgement Relief When Milk Won’t Flow.
  • 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. A cold compress such as frozen peas or crushed ice in a damp cloth placed against the sore, 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 slipped inside the bra cup around the affected breast can 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 plenty of fluids. Lawrence and Lawrence state bed rest should be mandatory during mastitis! 7.
  • Check with your health care professional if there is no improvement after 12-24 hours.

Engorgement due to 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 area. For more information about preventing engorgement and how to deal with it see Engorged Breasts.

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.

Medication for mastitis


Ibuprofen and paracetamol are compatible with breastfeeding 8. The Academy of Breastfeeding Medicine explains:

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.


Your health care professional will be able to prescribe compatible antibiotics for a bacterial infection if symptoms are not improving after 12-24 hours of a mastitis action plan, or if the mother is very poorly 9. The organisations below discuss specific antibiotic choices and doses and currently recommend a 10–14 day course of antibiotics:


Arroyo et al 10 compared giving mothers strains of Lactobacillus species isolated from breast milk with conventional antibiotic treatment. They found that women who took the probiotics improved more and had lower recurrence of mastitis than those who took antibiotics. However, Amir et al 11 describe a number of concerns about the validity of Arroyo’s study, and similar trials, and call for high quality randomised control trials to establish whether probiotics are an effective treatment for mastitis.

Recurrent Mastitis

If you keep getting episodes of mastitis or blocked ducts your IBCLC lactation consultant can be very helpful to identify the most likely reasons. They will review your history, and check whether your positioning, latch or breastfeeding management could be the cause for mastitis to keep returning. Other risk factors for recurring mastitis include:

  • Incomplete treatment of the original infection or mastitis which is not treated promptly 12
  • Mothers who have a previous history of mastitis 13.
  • Breastfeeding on a schedule (e.g. timing or limiting feeds)
  • Stopping breastfeeding abruptly on the affected side during an episode of mastitis
  • Recurring blocked ducts
  • Previous breast surgery e.g. breast implants, reduction surgery or any other causes of scarring within the breast.
  • Mother being anaemic or very stressed 14
  • Dietary fats. Recurrent blocked ducts and associated mastitis may be worsened by a diet that is rich in saturated fats. Eating more polyunsaturated fatty acids and adding lecithin to the mother’s diet may be helpful (Lawrence, 2016). It is important to get a healthy balance of essential fatty acids in the diet however. A diet that is very high in omega-6 fatty acids but has markedly fewer anti-inflammatory omega-3 fatty acids may promote inflammation in the body including breast tissue15.

Treatment for recurrent mastitis

Doctors Lawrence and Lawrence 16 recommend antibiotic treatment should continue for at least 10-14 days to prevent recurrence. If it does come back again, they advocate:

  • Culture specimens from breast milk and from the baby’s throat
  • Fully review the circumstances and possible causes of recurrence
  • Adequate rest and stress management for mother
  • Complete breast drainage
  • Consider chronic bacterial infection, secondary fungal infection, underlying breast disease such as a cyst, tumour or other medical cause.

Not mastitis?

Check with your health professional if mastitis does not improve with treatment. Although rare, other conditions such as cellulitis or inflammatory breast cancer can be mistaken for mastitis 17Subacute mastitis may be mistaken for thrush—see Thrush on Nipples for more information.

Frequently asked questions

#1 Can I continue breastfeeding my baby if I have mastitis?

Yes, even if antibiotics are needed, breastfeeding can continue during mastitis 18. Antibodies in breast milk will help protect the baby from any infection and stopping breastfeeding abruptly could cause more problems. Breast milk may taste slightly salty from a breast with mastitis but this doesn’t usually pose a problem to the 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.

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

#2 What can I do if my baby can’t latch or my milk won’t flow?

Sometimes engorgement behind the nipple can change the nipple shape making it difficult for your baby to latch and having the effect of someone stepping on a hose, stopping the flow of liquid (i.e. breast milk!). 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.

#3 What is the treatment for blocked milk ducts?

An untreated blocked duct can lead to mastitis. Treatment for a blocked duct is very similar to treatment for relieving engorgement or mastitis, but lecithin and other supplements are sometimes suggested, see Blocked Milk Duct for more information. 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 ideas of how to clear it.


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 for treating mastitis that are 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 and contact your medical professional.