Written by:

Dr Aynsley Cresswell


Dr Cresswell is a general practitioner in the North East having recently moved to Yorkshire from Oxford. Aynsley has a special interest in women's and sexual health, and she has gained diplomas in both of these specialist areas. She has a keen interest in teaching and also enjoys caring for patients with long-term health conditions in her day-today practice.


In this article:

  • Symptoms and treatment of mastitis
  • What is mastitis and who suffers from it?
  • Mastitis symptoms
  • What causes mastitis?
  • Treating mastitis
  • Preventing mastitis
  • Main points:


Symptoms and treatment of mastitis

Up to 30% of breast-feeding mothers will get this painful condition. Here we discuss how to prevent it, how to recognise the symptoms of mastitis, how to treat it and how to breastfeed when suffering from the condition.

What is mastitis and who suffers from it?

Mastitis is a painful inflammatory condition of the breast which normally affects breastfeeding women, mainly in the first three months after giving birth. Around 10–33% of lactating women develop mastitis. However, it is possible to develop mastitis even if you are not breastfeeding (due to an infection in the breast) and in some rare cases men can also be affected. In breastfeeding women, milk stasis (accumulation/blockage) is the primary cause of mastitis. This build-up of milk results in an inflammatory response (your body attempting to deal with the excess milk) which makes your breast tissue inflamed and painful. There may also be some redness around the tender area, and you may also notice firmness or a lump.

Sometimes you can get another infection on top of mastitis. In this case you may feel flu-like symptoms with aches and pains, a fever or simply feel generally rundown.

Mastitis symptoms

Usually, mastitis will affect only one of your breasts, but it can occasionally affect both. Symptoms can come on very quickly and can include some (or all) of the following:

  • A red area on your breast that can be swollen, hot and painful to touch.
  • A breast lump or a hard area on your breast (which may feel wedge-shaped).
  • A burning pain that might be in your breast all the time, or only when you breastfeed.
  • Nipple discharge, which can be white or may contain streaks of blood.
  • Flu-like symptoms, including chills and a fever.

What causes mastitis?

Mastitis is usually caused by excess milk in your breast — this happens when milk collects faster than it is being removed. This creates a build-up in your milk ducts (known as “milk stasis”) and can be caused by:

  • Your baby’s latch not being in the correct position.
  • Infrequent let-down (not feeding often enough or missing some feeds, which is why mastitis can happen during weaning and any period in which you are stopping breastfeeding).
  • Not emptying the breasts fully at feeds.
  • Feeding from one side more than the other.
  • An injury that damages a milk duct or gland.

There is no evidence that breast size is related to the incidence of mastitis. However, age may play a role. One study identified by the World Health Organization (WHO) showed that women aged 21–35 years are more likely to develop mastitis than those outside this age group.

Furthermore, infection can occur on top of mastitis. This is because it is more likely that bacteria will get into the breasts if you have sore and cracked nipples or an injury to the nipple. Smoking can also increase the chance of infection.

Treating mastitis

Importantly, don’t suffer on your own. Try to get some breastfeeding support if you can. This can be from a midwife at your hospital or from a specialized lactational consultant. Ensuring a good latch, as well as regular feeding/expressing and optimising your breastfeeding position may be all that is needed.


As mastitis is due to an excess of milk, it’s important to ensure the breasts are being emptied regularly. In fact, you should try to continue feeding if at all possible. Further tips to self-treat mastitis include:

  • Aim to feed 8-12 times a day and through the night. Begin every feed by offering the affected breast first.
  • Massage your breast to clear any blockages if it is not too painful — gently press from the affected area towards your nipple. This will help to drain the milk.
  • A warm compress (soak a cloth in warm water) applied to your breast before a feed can help with the pain and encourages the let-down reflex.
  • If there is any leftover milk in your breasts after feeding, express it by hand or with a pump.
  • For some, it might be easier to express milk to feed the baby and to avoid breastfeeding until the pain resolves.
  • Get plenty of rest and drink lots of fluids. Avoid tight-fitting clothing or bras until you feel better as they can restrict milk flow. If you have pain, you can take paracetamol or ibuprofen; these are both very safe for breast-feeding. In addition to warm compresses, warm showers and baths can help too.


Mastitis without infection does not need antibiotics. If the breast soreness lasts for more than a few days or if you feel unwell at all, it may be a sign that you have developed an infection and should see your GP. Your GP may prescribe a course of antibiotics which will normally clear the infection within a few days. Don’t worry, even If you have an infection in your breast, breastfeeding will not harm your baby, although it can change the taste of your milk slightly. A very small amount of antibiotics may get into your breast milk but again, this is not a risk to your baby.

If your symptoms do not settle within 48 hours of starting a course of antibiotics, contact your GP. It may be that your infection is not responding to the first choice of antibiotic, or that you need an alternative diagnosis, such as a breast abscess (a walled-off pocket of infection). The GP may consider sending a sample of your breast milk to the lab for testing (to check the bacteria in order to determine which antibiotic it may respond to). Once your GP receives the results of this test, they may offer a different antibiotic treatment.

Preventing mastitis

The World Health Organization (WHO) found that more than half of women with lactational mastitis had experienced at least one previous episode.

Things you can do to help prevent mastitis include:

  • Breastfeed exclusively (use expressed milk rather than formula to top up) if you can and be sure to breastfeed often and “on demand” — breastmilk can build up if there are long gaps between feeds.
  • Ensure your baby has a good latch: experiment with varying breastfeeding positions to work out which is most comfortable for you. You can speak to your health visitor about this.
  • Take your baby’s cues for when they are finished feeding: usually, they will release their latch when finished.
  • If you are thinking of stopping breastfeeding altogether, or if you are cutting down, try to do so gradually by reducing the number of feeds slowly: don’t abruptly wait longer between feeds.
  • If possible, avoid pressure on your breasts by wearing loose clothing and try to avoid tight or restrictive bras.
  • Ensure good hygiene measures with frequent handwashing; discard potentially infected nipple ointments/creams; rinse the nipple area before and after every feed; and ensure your breast pump is cleaned with hot soapy water (or sterilised) and air dried after each use.

If you would like confidential breastfeeding advice, call the National Breastfeeding Helpline 0300 100 0212 (9.30am-9.30pm, seven days a week).

Main points:

  • Mastitis is a painful and swollen breast due to a build-up of milk.
  • Treatment is about emptying the breasts regularly and ensuring a good breast-feeding technique.
  • You can continue breast-feeding with mastitis and an infection in the breast.
  • To soothe pain and inflammation, avoid tight-clothing, use a hot compress and take simple over-the-counter painkillers such as paracetamol or ibuprofen.
  • If your symptoms are persistent, getting worse or you feel unwell, you should contact your GP as you may have an infection in addition to mastitis.
  • Infection needs to be treated with antibiotics and it is safe to continue breast-feeding during this time.

Academy of Breastfeeding Medicine (2014) ABM Clinical protocol #4: mastitis, revised March 2014. Breastfeeding Medicine 9(5), 239-243
Amir, L.H. (2014) Managing common breastfeeding problems in the community. BMJ 348.
BMJ (2014) Best practice – mastitis and breast abscess. BMJ Best Practice. BMJ Publishing Group. http://bestpractice.bmj.com
Breast Cancer Care (2013a) Periductal mastitis. Breast Cancer Care. https://www.breastcancercare.org.uk
Dixon, J. and Khan, L. (2011) Treatment of breast infection. BMJ 342.
WHO (2000) Mastitis. Causes and management. World Health Organisation. http://www.who.int
Dixon, J.M. (2013) Breast Infection. BMJ Dec 16(347).

Important – If you or your child are unwell you should seek medical advice from a professional – contact your GP or visit an A&E department in an emergency. While My BabyManual strives to provide dependable and trusted information on pregnancy and childcare 24/7 via our website pages, we cannot provide individual answers to specific healthcare questions.