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Mastitis while breastfeeding

Mastitis is an inflammation of 1 or both breasts. The pain, heat and swelling can be very intense.

You may notice a:

  • hard and painful lump
  • hot and red wedge-shaped area of engorgement (when your breasts get too full of milk)
  • raised temperature

Sometimes a bacterial infection in another part of the body can lead to mastitis.

Causes of mastitis

Causes of mastitis include:

To reduce the risk of mastitis, make sure your baby is well positioned and attached.

Positioning and attachment

Types of mastitis

These can range from unrelieved engorgement to:

  • non-infective mastitis
  • infective mastitis

Non-infective mastitis symptoms

Non-infective mastitis can happen when a milk duct or lobe is not draining well and becomes inflamed.

You will feel generally well.

Symptoms develop gradually and may include:

  • your breast feels hot and sore (mainly in 1 area of the breast)
  • a slight rise in temperature - up to 38.3 degrees Celsius

Non-urgent advice: Contact your GP if

your temperature:

  • lasts longer than 24 hours
  • goes higher than 38.3 degrees Celsius

Infective mastitis symptoms

With infective mastitis, your breast may feel tender, hot and swollen.

Other symptoms may include:

Non-urgent advice: Contact your GP if:

  • you have a fever or flu-like symptoms that do not ease after 24 hours - you may have a bacterial infection

Breastfeeding with mastitis

It is important to continue breastfeeding. Try starting on the affected breast if possible.

Your breast milk may not release if you are in pain. If this happens, try breastfeeding on the unaffected breast. Move back to the affected breast as soon as the breast milk starts releasing.

Mastitis may cause your breast milk to taste a little salty. Your baby may notice this slight change. But it does not last long.

Breastfeeding may be too painful. If so, gently express milk from the affected breast either by hand or using a pump.

If you use a pump to express, put it on a low setting to start. Gradually turn up the setting as far as you can without it being painful.

How to express breast milk

Expressing breast milk using a pump (video)

Treating mastitis

There are things you can do to help ease the symptoms of mastitis.

Gentle massage

Massage your breasts very gently in a circular motion. Apply a light touch when you do this and use the flat of your hand. Continue the gentle touch all the way towards your armpit.

Do not apply too much pressure when massaging. This can cause damage and scarring to sensitive breast tissue. It can also increase the risk of more blockages.

Pain-relief medicine

Use anti-inflammatory pain relief such as ibuprofen (unless there is a medical reason not to). This will relieve symptoms such as a raised temperature, body aches and a painful and aching breast.

Anti-inflammatory pain relief

Cold comfort

Use a cold pack (ice wrapped in cloth) or cool moist facecloth to reduce swelling and relieve pain - after a feed or in between feeds. Do this for 10 minutes, every 30 minutes if needed.

Try gentle warmth

You may find adding gentle warmth to your breast for a few minutes gives some comfort. You can do this with warm water in the shower or with a warm face cloth.

Gently massage the area around your armpits and the front of your neck. This improves drainage in your lymph nodes and can help to reduce swelling.

Avoid excessive heat as this may cause inflammation. It can affect your milk flow too.

Choose heat or cold depending on what feels most soothing.


You may need an antibiotic if you have infective mastitis. Take the full course as prescribed, even if you feel better after a few doses.


Get as much rest as possible. Lie down when feeding. Sleep when your baby is sleeping. Ask your partner, family or friends to help. Eat well if you can and drink plenty of fluids.


  • do not wear tight, restrictive clothes and bras that can restrict milk flow

  • do not overfeed or express more than your baby needs

  • do not take aspirin

  • do not stop breastfeeding suddenly - find out how to stop breastfeeding

  • do not apply oils, soaks or creams to your breast


If a breast lump does not get smaller within a week, ask your GP to examine it

Milk supply

You may notice that when the mastitis clears up, you produce less milk than before the infection.

This is temporary and your milk supply will return. Feeding on cue and having lots of contact with your baby will help.

If you have concerns about your milk supply, contact your public health nurse or lactation consultant for advice.

If your symptoms do not improve, talk to your GP or lactation consultant.

Concern about your milk supply

Get breastfeeding support

For help and advice on a sore breast or mastitis, contact your:

Ask our breastfeeding expert

Page last reviewed: 9 December 2023
Next review due: 9 December 2026