The Royal Womens Hospital defines mastitis as inflammation of the breast that can lead to infection.

Mastitis differs from a blocked duct as a blocked duct is not an infection. It can be difficult to differentiate between a blocked duct and mastitis because sometimes the skin covering the blocked duct can appear red and inflamed however usually not as red as with mastitis.


  • Poor emptying of the breast
  • Poor attachment contributing to poor emptying of the breast
  • Over supply

Signs and Symptoms

  • Flu symptoms- fever, sore joints
  • A red area on the breast
  • Painful lump in the breast


  • Breastfeed on demand
  • Offer one breast until it is drained (or feels soft) before offering the second. If baby doesn’t drain both breasts offer the less drained breast at the next feed.
  • If signs of attachment issues are present (nipple pain, damaged nipples, misshaped nipples after breastfeed or clicking noise from the baby during the feed) see a Lactation Consultant for further assessment
  • If breasts remain full or lumps are present post feed express until breast feel soft once or twice a day
  • Avoid clothes that compress the breasts
  • Avoid offering formula or delaying/putting off breastfeeds
  • Consider eating fermented food (Kefir, fermented vegetables) or sourcing a reputable probiotic specific to breastfeeding


  • Continue breastfeeding from the affected side- your breast milk may taste saltier to the baby so he/she may refuse or become fussy when feeding from the effected side- if this occurs consider expressing and continue to gently encourage baby to breastfeed by offer effected breast at each feed
  • Massage lumps towards the nipple whilst feeding or expressing
  • Use heat pack prior to breastfeeding/expressing to encourage a let down
  • If breast pain is present post feed consider using a cold pack to reduce inflammation
  • Commence a good quality probiotic (preferably specific for breastfeeding)
  • Maintain adequate hydration
  • If symptoms have been present for <24 continue breastfeeding or expressing and attempt to drain the effected area of the breast/s- if feeling worse over the next 3 hours seek advice from GP or Midwife ASAP.
  • If symptoms have been present >24 hours seek advice from a GP- it is likely you will require some antibiotics
  • It is likely that it is safe to continue breastfeeding whilst on antibiotics however if you are located in Australia you can contact the King Edward Memorial Hospital pharmacy number (08)64582222 if you want to clarify or double check
  • Remember to seek medical attention early if your symptoms are not improving and if possible commence treatment at the first sign of mastitis