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Mastitis is a painful breast condition. Here we discuss its symptoms, treatment, how to continue breastfeeding with mastitis and how to help prevent it.

Mastitis symptoms usually develop quickly with signs of inflammation normally appearing in one breast, often alongside feeling like you have flu. It’s most common in women who are breastfeeding.

What is mastitis?

Mastitis causes a woman’s breast to become swollen, painful, inflamed and it might appear red or darker, depending on skin colour. It usually occurs within the first three months after giving birth (NHS Choices, 2019a).

Mastitis symptoms

Mastitis usually occurs in one breast, but may affect both. Symptoms usually develop quickly and might include:

  • a lump on the breast that is sore and hard (also see our article about blocked milk ducts); it might feel hot and painful to touch, and the area may be red or dark, although this can be more difficult to see on darker skin
  • a burning pain that might be continuous or happen while you’re breastfeeding

  • nipple discharge that's white or contains traces of blood

  • flu-like symptoms, for example feeling tired and achy, and having a fever and chills.

    (La Leche League GB, 2016; NHS Choices, 2019a)

What causes mastitis?

Mastitis is often caused by a build-up of milk in the breast – called milk stasis.

You might get milk stasis and mastitis because:

  • your baby is having problems sucking
  • your baby is not positioned well or attaching well to the breast during feeds
  • you have cracked nipples that have become infected
  • your baby isn’t feeding frequently or is missing feeds
  • something is putting pressure on the breast or has bruised it; for example, a tight bra or tight clothing, bag strap, seat belt, baby carrier.

    (La Leche League GB 2016; Essential Parent, 2016; NHS Choices, 2019a)

In some cases, this build-up of milk can become infected with bacteria. This is called infective mastitis and you might need antibiotics to treat it.

Continuing to breastfeed with mastitis

If you develop mastitis, continuing to breastfeed will help you by getting the milk flowing, improving your symptoms and it won’t harm your baby. The affected breast might produce less milk for a few days. But encouraging your baby to breastfeed frequently from the affected breast might help to clear the blockage and help your milk production to increase quickly. You could try to:

  • increase the frequency of feeding to remove as much milk as possible. Express by hand or with a breast pump if your baby is unable to feed

  • start feeding with the affected breast first

  • express milk between feeds

  • make sure your baby is positioned and latching well for every breastfeed (seek help from NCT breastfeeding counsellors, or consult your midwife, health visitor or other professional breastfeeding support)

  • try different feeding positions so your baby stimulates the blocked area more effectively

  • before feeding, try softening your breast by expressing a little milk, which might make it easier for your baby to feed well

  • massage the affected area in a warm shower or using a warm compress before feeding.

    (La Leche League, 2016; NHS Choices, 2019b)

Mastitis treatment

Mastitis is usually easy to treat, and most women recover well and quickly. Some self-help measures can be helpful, such as:

  • making sure your baby is positioned and attached well to your breast

  • continuing to breastfeed even if you have an infection. This will help relieve your symptoms and won’t harm your baby

  • it might help to breastfeed more frequently than usual

  • getting lots of rest and relaxation

  • staying hydrated

  • using paracetamol or ibuprofen for relief from pain or fever

  • avoiding tight or restrictive clothes or bras until symptoms improve (see our article about maternity and nursing bras for more tips).

(NHS Choices, 2019b)

Contact your GP if you think you might have mastitis. In the meantime, continue with self-help measures before your appointment. You might need antibiotics to treat mastitis, and if you're breastfeeding, you'll need antibiotics that are safe to use while breastfeeding. You might also need to contact your GP if you:

  • continue to feel feverish or if your temperature rises above 38.4°C

  • see pus or blood in your milk

  • have a cracked nipple that looks infected

  • see red streaks on your breast or your breast becomes red, hot and swollen.

    (La Leche League, 2016; Essential Parent, 2017; NHS Choices, 2019a)

Some women with mastitis or recurrent mastitis can develop a breast abscess – a collection of pus, which might need to be drained surgically (NHS, 2019b). So, if you think your mastitis hasn’t cleared within 24 hours or it returns, you might want to talk to your GP.

Preventing mastitis

If you find you have recurring mastitis, it's a good idea to seek breastfeeding support to help make adjustments to your baby’s latch. It might also be helpful to check that your baby doesn’t have any underlying medical conditions, such as a tongue-tie. Try to take these steps to help prevent mastitis:

This page was last reviewed in March 2021

Further information

We support all parents, however they feed their baby. If you have questions, concerns or need support, you can speak to a breastfeeding counsellor by calling our support line on 0300 330 0700, whether you are exclusively breastfeeding or using formula milk.

Breastfeeding counsellors have had extensive training, will listen without judging or criticising and will offer relevant information and suggestions. You can also find more useful articles here.

You might find attending one of our Early Days courses helpful as they give you the opportunity to explore different approaches to important parenting issues with a qualified Postnatal Practitioner and other new parents in your area.

Make friends with other parents-to-be and new parents in your local area for support and friendship by seeing what NCT activities are happening nearby.

National Breastfeeding Line (government funded): 0300 100 021.

Best Beginnings - Bump to Breastfeeding DVD Chapter 7 'Overcoming Challenges'. Managing Breastfeeding – dealing with difficult times.

Essential Parent. (2018) Mastitis. Available from: [Accessed 19th March 2021].

La Leche League GB. (2016) Mastitis. Available from: [Accessed 19th March 2021].

NHS Choices. (2019a) Mastitis. Available from: [Accessed 19th March 2021].

NHS Choices. (2019b) Mastitis treatment. Available from: [Accessed 19th March 2021].

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