Mastitis while breastfeeding

Mastitis is an inflammation of the breast. 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)

Causes of mastitis

Causes of mastitis include:

Types of mastitis

There are 2 types of mastitis:

  • non-infective mastitis
  • infective mastitis

Non-infective mastitis symptoms

With non-infective mastitis, you will feel generally well and:

  • your breast will feel hot and sore mainly in one area of the breast
  • the symptoms are gradual, not sudden
  • only one breast will be affected

Infective mastitis symptoms

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

Other symptoms may include:

  • a fever or high temperature (38 degrees Celsius or higher)
  • chills
  • flu-like symptoms (aches and pains all over the body)
  • a tender, hot, swollen area of the breast
  • generally feeling unwell


Contact your GP immediately if you have flu-like symptoms with signs of a breast infection.

Breastfeeding with mastitis

If you can breastfeed your baby, 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.

Breastfeeding may be too painful. If so, use hand-expression or a breast pump to remove milk from the affected breast.

Expressing by pump or hand

It may help to fully remove the milk from your affected breast by expressing. You can do this by hand or by pump after the feed from the other breast.

If you're using a breast pump, remember to keep the pump and attachments clean. Follow hospital or home-use guidelines. Begin pumping on a low setting, then turn up the setting as far as you can take it without it being painful.

How to treat mastitis

Follow these steps to treat both non-infective and infective mastitis:

  1. Carefully wash your hands.
  2. Remove any source of pressure from your breast - for example, clothing or a bra that is too tight.
  3. Put a warm face cloth on your breast before feeding.
  4. Breastfeed regularly, beginning on the sore breast if possible.
  5. While breastfeeding, gently massage your breast behind the sore area.
  6. Drink plenty of fluids.
  7. When feeding your baby, try changing the feeding positions.
  8. If this doesn’t work, get into the shower. With your breast well-soaped, apply steady but gentle pressure behind the plugged area. Press toward the nipple.
  9. Watch out for signs of a developing breast infection. For example, a temperature, chills and aches throughout the body.


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

Other treatment for infective mastitis


Ask your GP or nurse if it's safe to take a non-steroidal anti-inflammatory medicine. For example, ibuprofen. This may relieve symptoms such as a temperature and a painful and aching breast.

Always take the full of course of any medications you are prescribed.

Breast massage

Put an edible oil or non-toxic lubricant on your fingers and massage the affected breast. This will help with breast milk removal. The massage should start from the blockage and move towards the nipple.

One way of doing this is a 'bag of marbles massage’. This involves holding your breast with interlaced fingers. With gentle kneading motion, shift the 'marbles' all around the inside of the ‘bag’ or breast. You should do this several times a day.

Apply heat

Putting heat on your breast before breastfeeding may help with the release and flow of the breast milk. You can do this with a warm shower or a hot pack.

When you have finished feeding, put a cold pack on your breast to help with soreness and swelling.


It is important for you to rest and eat and drink well. Ask for help and support from your partner and family.

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. Lots of feeding and contact with your baby will help.


If your symptoms do not improve, talk to your GP.

Getting support

There is a wide range of breastfeeding support available in Ireland. Contact your local breastfeeding support group or talk to your GP or public health nurse.

Page last reviewed: 19 March 2019
Next review due: 19 March 2022