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HealthInfo Waitaha Canterbury

Mastitis (inflamed breasts)

Mastitis (inflamed breasts) is quite common in women who are breastfeeding. A build-up of milk in your breasts can make them inflamed, red and painful. Sometimes this built-up of milk can become infected with bugs (bacteria), which needs to be treated with antibiotics.

If you think you have mastitis, it's important to see your midwife or GP to get it treated.


Some breastfeeding women can get a breast abscess. If you feel any hard, red, painful areas in your breast, see your GP or midwife as soon as you can.

Symptoms of mastitis

Watch out for the signs of mastitis, especially if you've had it in the past. Get help as soon as you notice any of these:

Preventing mastitis

There are several things you can do to avoid mastitis. Make sure your pēpi (baby) is latching at your breast correctly and is effectively removing milk. Ask your midwife to check your technique or consider seeing a lactation consultant.

You can usually see a lactation consultant for free if you're referred by your midwife or GP. Or you may choose to pay to see a private lactation consultant.

Being stressed, exhausted, or both can mean your immune system doesn't work so well, increasing your chances of getting mastitis. So, try to avoid these if you can. Use any help available to you – before you think you need it – and rest while your pēpi rests.

Follow the cues or signs from your pēpi that they're ready to breastfeed, and do not miss feeds or cut them short. This helps your breasts to empty of milk, so it doesn't build up and cause mastitis. Signs that they're ready to feed can be nuzzling, hand-sucking or mouthing (where they open their mouth and turn their head). Crying is usually the last cue for feeding, and it may be difficult to get your pēpi to latch properly if they're crying.

If your breasts are feeling full and uncomfortable, it's okay to wake your pēpi up to feed. If they're too sleepy to feed, you can try expressing a small amount of milk by hand. If you need help with this, ask your midwife, lactation consultant or breastfeeding support person or organisation.

Avoid giving formula top-ups, as the next time your pēpi feeds, they may not remove enough milk, so increasing your discomfort.

Do not use a breast pump unless you've spoken to your midwife, Well Child nurse, GP or practice nurse about it, as using a breast pump may cause you to make too much milk. Using a breast pump without a good reason may cause mastitis and other problems such as damaged nipples.

Treating mastitis

If you have mastitis, your midwife, lactation consultant or breastfeeding support person will check your feeding technique and how well your pēpi baby is feeding. The best way to treat mastitis is to frequently feed your pēpi from the affected breast so milk fully drains from it. You may also need pain relief or antibiotics.

It's possible you may need to use a breast pump or express milk by hand to make sure you're removing all your milk. Your GP, practice nurse, midwife, Well Child nurse or lactation consultant can give you more information on breast pumps.

If your midwife or doctor are concerned that you may have an infection in your breast, they will prescribe antibiotics. This is more likely if you have a fever or flu-like symptoms. If you also have a hard red lump in your breast, you may have a breast abscess, which may need to be drained.

Self-care for mastitis

If you have mastitis, there are several things you can do.

Blocked duct

If you have a blocked duct, you may feel a painful area in one breast. You may also feel a lump. If you do not have any other symptoms, continue breastfeeding, apply heat to the affected area, massage it gently and rest as much as possible.

Let your midwife, GP, lactation consultant or other breastfeeding support person know if it doesn't get any better or if you start feeling unwell. Symptoms such as a headache, aches and pains, and feeling like you're coming down with the flu or a cold may mean that you have an infection that needs further treatment.

When you have a blocked duct or a breast infection, it's important that your pēpi breastfeeds effectively and often to remove milk from your breasts.

Written by HealthInfo clinical advisers. Last reviewed December 2021.


See also:

Getting help with breastfeeding

Page reference: 45601

Review key: HIBRF-24381