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Blocked milk ducts and mastitis fact sheet

Blocked milk ducts and mastitis

What is a blocked duct?

A blocked duct is an area or segment of the breast where milk flow is obstructed (milk stasis) causing a tender lump or spot in the breast.

What is mastitis?

Mastitis is an inflammation of the breast which is usually caused by a blocked milk duct that hasn’t cleared, or a damaged nipple. Infection may or may not be present.


Blocked duct

Local symptoms

  • A reddened area or segment of the breast which becomes tender, hard and painful
  • Occasionally, there can be localised tenderness or pain without an obvious lump
  • May occur with a painful white blob/spot on the nipple

Systemic symptoms

  • Occasionally, a low-grade fever may be present, usually less than 38.5oC


Local symptoms

  • A reddened area or segment of the breast which becomes tender, hard and painful
  • Occasionally, there can be localised tenderness or pain without an obvious lump
  • Usually more intense pain/heat/swelling than a blocked duct
  • There may be red streaks extending outward from the affected area

Systemic symptoms

  • Fever of 38.5oC or greater
  • Flu-like symptoms including joint aches, pains and lethargy. Often rapid onset of symptoms

It’s important to start treatment as soon as you feel a lump or sore spot on your breast


  • The most important part of treatment is frequent milk removal by breastfeeding or expressing (eight or more times each 24hrs)
  • Milk supply from the affected breast may decrease temporarily. This is normal – extra feeding or expressing will return your milk supply to normal.
  • You may express strings of thickened or fatty looking milk.
  • After the mastitis has resolved, it is common for the affected area to feel bruised or remain reddened for a week or so afterwards.
  • Your breast milk may taste salty due to increased sodium and chloride content. If your baby is breastfeeding, they may fuss due to this change in taste. If your baby is being fed by a naso-gastric tube they will not notice any difference.

Management before feeding or expressing

  • Apply warmth to the breast just before a feed (for up to 10minutes) or try expressing to help trigger a let-down. Warmth can be provided by a warm shower or a well-covered heat pack.
  • Gentle massage may also help trigger a let-down.
  • Hand express if needed to soften the areola to help your baby latch well.

Management during feeding or expressing

  • Start feeding or expressing on the sore breast first, but if too painful, start feeding or expressing on the less-sore side until your milk let-down occurs and then change sides.
  • Ensure your baby is latching well and ask for assistance if you are experiencing any difficulties.
  • Continue to massage your breast during feeding/expressing.

Management after feeding or expressing

  • If your baby has not drained the breast well during the feed, continue to massage and express until the breast feels well-drained.
  • If your baby has not been feeding effectively, you can feed this additional milk to your baby.
  • Cold packs can be applied to the affected breast for up to 10 minutes to reduce pain and inflammation.

Pain medication

A non-steroidal anti-inflammatory drug such as ibuprofen provides the most-effective reduction in symptoms such as pain and inflammation. Paracetamol can be taken in conjunction with ibuprofen. Use as directed.


  • Antibiotics are not needed to treat a blocked duct.
  • If you have been unable to relieve the symptoms of a blocked duct after 12-24 hours, or if you develop a fever, you should see your GP for further management.
  • If antibiotics are required, it is usually still safe to continue breastfeeding or expressing milk for your baby. Check with your doctor or pharmacist.
  • Consider taking a probiotic to reduce the risk of thrush.

Tips to avoid further problems

  • Do not wear bras or other clothing that is too tight.
  • Avoid sleeping on your stomach.
  • Do not go for long periods without either breastfeeding or expressing.
  • Rest when you are able.
  • Drink adequate fluids.
  • Ensure correct attachment.
  • Ensure the breast pump is positioned correctly.
  • Regularly examine your breasts for lumps and massage these while feeding or expressing.
  • Breastfeed as often as your baby needs (normally eight-to-12 times in 24hrs).

You should not try weaning if you have a blocked duct or are suffering mastitis. You must continue to remove milk from your breasts at this time in order to reduce the risk a breast abscess.

Contact us

Lactation Service, Division of Medicine
Level 9, Queensland Children’s Hospital
501 Stanley Street, South Brisbane
t: 07 3068 1807
t: 07 3068 1111 (general enquiries)

In an emergency, always call 000.

If it’s not an emergency but you have any concerns, contact 13 Health (13 43 2584). Qualified staff will give you advice on who to talk to and how quickly you should do it. You can phone 24 hours a day, seven days a week.


1.   Academy of Breastfeeding Medicine (2008) ‘ABM Clinical protocol #4: Mastitis revision, May 2008.’ Breastfeeding Medicine 3(3):177-180

2.   Mannel R, Martens P, Walker M.(2013) Core Curriculum for Lactation Consultant Practice (3rd edition) Burlington, MA: Jones and Bartlett Learning.

3.   Betzold C. (2007) An update on the recognition and management of lactational breast inflammation. Journal of Midwifery and Women’s Health, 52, 595-605.

4. ‘Recurrent mastitis or plugged ducts’ cited Jan 2015

5. ‘Mastitis’ cited Jan 2015

6. ‘Mastitis’ cited Jan 2015

7.   National Health and Medical Research Council (2012) Literature Review: Infant Feeding Guidelines. Canberra: National Health and Medical Research Council. ISBN Online: 1864965762

Resource No: FS127. Developed by Lactation Service. Updated: February 2015

All information contained in this sheet has been supplied by qualified professionals as a guideline for care only. Seek medical advice, as appropriate, for concerns regarding your child’s health.