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  4. Mastitis

Mastitis

Key facts

  • Mastitis is inflammation of the breast and can happen at any time while you are breastfeeding.
  • Mastitis causes redness, pain and swelling in the affected breast, as well as general flu-like symptoms such as fever, muscle aches and headaches.
  • It's important to see your doctor or midwife as soon as possible if you feel you may have mastitis.
  • If you have mastitis, continue to breastfeed your baby from your affected breast.
  • Help prevent mastitis by breastfeeding your baby as often as they need, making sure your baby is latching well, avoiding supplement feeds unless medically recommended and resting when you can.

On this page

  • What is mastitis?
  • Is mastitis infectious?
  • What are the symptoms of mastitis?
  • What causes mastitis?
  • When should I see my doctor or midwife?
  • How is mastitis treated?
  • Can I prevent mastitis?
  • What are the complications of mastitis?
  • Resources and support

What is mastitis?

Mastitis is inflammation of the breast. Mastitis most often occurs during the first 4 weeks of breastfeeding (Opens in new tab), but can happen at any stage. Some people are more likely to develop mastitis and can have repeated episodes.

Is mastitis infectious?

If the inflammation in your breast is not treated early, bacteria from your skin can get into your milk and cause a bacterial infection (Opens in new tab). This is called bacterial mastitis. If this happens, you are not contagious. Your baby will not catch an infection from your milk.

What are the symptoms of mastitis?

If you develop mastitis, you may experience some of these common symptoms:

  • flu-like symptoms — for example, fever (Opens in new tab), muscle aches (Opens in new tab), headaches (Opens in new tab) and nausea (Opens in new tab)
  • pain and tenderness in your breast
  • a lump or lumps in your breast
  • a red or swollen area of your breast

Your symptoms can range from being mild to severe.

CHECK YOUR SYMPTOMS — Use the Symptom Checker and find out if you need to seek medical help.

What causes mastitis?

It's not clear exactly what causes mastitis, but there are risk factors that can increase your chances, including:

  • poor attachment to the breast during breastfeeding — for example, if your baby has tongue tie
  • nipple damage
  • breast engorgement
  • changes in feeding patterns — a sudden long break between breastfeeds, missing feeds or limited time sucking at your breast
  • stopping breastfeeding too quickly
  • wearing an overly tight bra or tight clothing

When should I see my doctor or midwife?

You should see your doctor (Opens in new tab) or midwife if you think you have symptoms of mastitis. If you have a diagnosis of mastitis, and symptoms are not improving after 24 to 48 hours, see your doctor or midwife again. You may have developed bacterial mastitis, and may need treatment.

FIND A HEALTH SERVICE — The Service Finder can help you find doctors, pharmacies, hospitals and other health services.

How is mastitis treated?

If you have mastitis, it is important to keep your milk moving. You can do this by breastfeeding or expressing breast milk.

Treatment may also include the following:

  • Rest when you can — ask friends, family or other supports to help with daily tasks so you can focus on recovering.
  • Reduce pain and swelling — apply gentle warmth (but not too warm or hot) to the breast before feeding, and apply a cold pack after feeding to help reduce swelling and discomfort.
  • Avoid pressure on the breast — if you massage the breast, do so gently.
  • Use pain relief if needed — paracetamol and ibuprofen are safe to take while breastfeeding. Ibuprofen may be especially helpful because it also reduces inflammation.
  • If your symptoms have not improved within 24 to 48 hours, your doctor may prescribe antibiotics. It is important to continue breastfeeding or expressing breast milk while taking antibiotics.

Keep your milk moving

If you have mastitis, try to continue to breastfeed your baby from the affected breast as you usually do. This helps relieve your symptoms and maintain your milk supply. You do not need to try to remove more milk than usual.

Here are some tips to help keep your milk moving:

  • Try to offer your affected breast first at every feed. This helps prevent your symptoms from getting worse and protects your supply.
  • Check how your baby is feeding. Make sure that your baby is positioned well and latches well at your breast. You should feel comfortable when you breastfeed. If you are unsure, seek advice and support from your midwife, child and family health nurse or lactation consultant.
  • Gently warm and stroke your breast just before a feed to encourage your let-down reflex.
  • Avoid rubbing or unroofing (opening) a white spot (milk blister), unless it is done by your health professional.

How can I relieve inflammation and other symptoms?

To reduce inflammation and other symptoms, your doctor or midwife may recommend:

  • applying a cool pack to the affected area on your breast
  • taking paracetamol (Opens in new tab) or ibuprofen (Opens in new tab) to relieve pain and inflammation. These medicines are safe for most people while breastfeeding (Opens in new tab).

You are no longer encouraged to use massage or excess warmth to relieve your symptoms.

You do not need to 'massage out' any lumps from your breast. This can damage your breast tissue. Milk from your inflamed breast can appear thicker or different. This milk is safe for your baby. It will return to normal when your breast heals.

Treating mastitis as quickly as possible is important to prevent your symptoms from getting worse.

Can I prevent mastitis?

Here are some tips that may reduce your chance of developing mastitis:

  • Breastfeed your baby as often as they need — this helps keep your milk moving. Avoid skipping feeds if possible.
  • Make sure your baby is positioned well and latches well at your breast.
  • Use breast pumps and nipple shields only when you need them and seek advice from a lactation professional.
  • Try to avoid supplementary feeds when you can. If you need to temporarily express breast milk, try to mimic your baby's feeding pattern.
  • Avoid wearing tight bras or clothing.
  • Avoid giving your baby formula or other breast milk substitutes, unless there is a medical reason.
  • It is important to learn how to recognise the signs and symptoms of mastitis, so that you can treat your symptoms as early as possible.
  • In the first weeks and months after your baby is born, try to rest when you can and seek support when you need it.

What are the complications of mastitis?

If you have mastitis that is not treated, you may develop a breast abscess (Opens in new tab) that may need to be drained by a surgeon.

Mastitis is also one of the main reasons why people stop breastfeeding early. This is because mastitis can make you feel physically unwell, and can also affect your mental health. Mastitis can cause frustration, fatigue (Opens in new tab) and stress (Opens in new tab). It can increase your chance of postnatal depression.

If you are struggling emotionally or feeling down, contact your maternity care provider. You can also call the Australian Breastfeeding Association breastfeeding helpline (Opens in new tab) for information and support from qualified breastfeeding counsellors on 1800 mum 2 mum (1800 686 268).

If you are finding breastfeeding difficult, a lactation consultant can provide practical support and help you manage mastitis while continuing to breastfeed if you choose to do so. Ask your doctor or midwife to recommend a lactation consultant in your area.

Resources and support

  • Learn more about mastitis on the Australian Breastfeeding Association website.
  • Read more about breastfeeding and looking after your baby during their first 3 months (Opens in new tab) on the Australian Breastfeeding Association website.
  • The Royal Women's Hospital has a collection of resources about common breastfeeding challenges (Opens in new tab), and how to manage them.
  • Call healthdirect on 1800 022 222 at any time to speak to a registered nurse (known as NURSE-ON-CALL in Victoria) for more information and advice.

Languages other than English

The Multicultural Centre for Women's Health offers free health education sessions (Opens in new tab) in many community languages.

Information for Aboriginal and/or Torres Strait Islander peoples

The Australian Breastfeeding Association has a collection of breastfeeding (Opens in new tab) resources for Aboriginal and/or Torres Strait Islander peoples.

Breastmilk Talk — 'Ngaminjang Djama' (Opens in new tab) is where Aboriginal and/or Torres Strait Islander mums have a yarn about the benefits of breastfeeding for mum and bub.

Speak to a maternal child health nurse

Call Pregnancy, Birth and Baby to speak to a maternal child health nurse on 1800 882 436 (Opens in new tab) or video call. Available 7am to midnight (AET), 7 days a week.

  • NSW Government — Mastitis (Lactational) Treatment (Opens in new tab)
  • Therapeutic Guidelines Australia — Lactational mastitis (Opens in new tab)
  • ABA — ‘Smoothing the bumps’ (Opens in new tab)
  • J Hum Lact. — Incidence of and Risk Factors for Lactational Mastitis: A Systematic Review (Opens in new tab) (Wilson E, Woodd S L., et al.)
  • North Metropolitan Health Service — Obstetrics and Gynaecology Clinical Practice Guideline – Breast Inflammation and infection: Mastitis and breast abscess (Opens in new tab)
  • PloS One. — The preventive and therapeutic effects of probiotics on mastitis: A systematic review and meta-analysis (Opens in new tab) (Yu Q, Xu C., et al.)
  • Front Psychiatry. — Increased risk of postpartum depression in women with lactational mastitis: a cross-sectional study (Opens in new tab) (Shen F, Zhou X., et al.)

Find out how we develop and review our content.


Last reviewed: May 2026

Need more information?

These trusted information partners have more on this topic.

Mastitis | Australian Breastfeeding Association

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Breastfeeding – mastitis and other nipple and breast problems | Better Health Channel

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