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breastfeeding baby

What does a blocked milk duct feel and look like? And what’s the best way to treat it? Find out everything you need to know here.

If you’re breastfeeding and you feel a small, tender lump in your breast, you might have a blocked milk duct. But what is it and what causes it?

What causes a blocked milk duct?

The glands that make milk in your breasts are divided into segments. A bit like an orange, in fact. Your milk ducts are the narrow tubes that carry milk to your nipple from each segment (NHS, 2019a).

You can get a blocked milk duct when any one of the breast segments doesn’t drain properly during a feed. It might happen if your baby is not taking your breast into their mouth deeply enough to feed effectively – a ‘shallow latch’. You might also get this if your baby has a tongue-tie (NHS, 2019a).

Sometimes a blocked milk duct can happen if your breast tissue is irritated for other reasons. This might be due to wearing a bra that’s too tight or a seatbelt across your breast on a very long car journey, or an awkward sleeping position where you’re putting weight onto your breast (NHS, 2019a).

Symptoms of a blocked milk duct

A blocked milk duct will cause the area of the breast around the blockage to feel hard and painful. It might also be red or darker, warm to the touch and slightly tender (NHS, 2019a). When your baby feeds on the side of the blocked duct, they might fuss because they’re getting your milk more slowly than usual (Mohrbacher, 2010).

It’s important to relieve a blocked milk duct as soon as possible or it might lead to mastitis (an inflammation of the breast) (NHS, 2019a)

Blocked milk duct treatment

Here are some ways to try to clear a blocked duct (they also work well for engorgement and mastitis):

Carry on breastfeeding

If you have a blocked duct, it is very important to carry on breastfeeding. This lowers the risk of the blockage developing into mastitis. If you were thinking of stopping breastfeeding anyway at this point, you’ll need to clear the blockage first and then stop gradually after that.

Get your baby’s positioning and attachment checked by someone who is skilled at offering breastfeeding support

Contact your nearest breastfeeding support group, or our Infant Feeding support line on 0300 330 0700. It’s open between 8am and midnight.

Other things to try include the following

Before feeding:

  • Gently massage the breast with your fingertips or palm of your hands, focussing on any lumps or sore areas (Mohrbacher, 2010).

When feeding:

  • It can be helpful to start feeding from the side with the blocked duct first, so your baby can soften the breast and help clear the blocked duct.
  • Women often find it helpful to try a different feeding position. One where the baby’s chin is near the blocked duct can be helpful.

(Mohrbacher, 2010)

After feeding:

  • If your baby falls asleep quickly, or is not feeding effectively, try breast compressions and/or express milk after a feed.
  • Apply a cold cloth or cool gel pack after feeds.

(Mohrbacher, 2010; NHS, 2016)

In general:

  • Breastfeed or express more frequently if your breasts are uncomfortably full. Long gaps between feeds can also make a blocked duct more likely to come back.
  • Although there are no studies about this, many women find it helpful to try to break up the blockage by using an electric toothbrush. The vibrations are said to be helpful. If you haven’t got one, a wide tooth comb can work too – gently rub towards the nipple. Doing this in a warm bath or shower has been found to be effective by some women. 
  • Rest as much as possible.
  • You can take paracetamol or ibuprofen while breastfeeding. If you’re taking other medicines, do check with a pharmacist. Aspirin should not be taken by women who are breastfeeding.

(Mohrbacher, 2010; NHS, 2016)

If the lump has not cleared after a day or two, or symptoms worsen (e.g. a fever and flu-like symptoms), do go and see your GP.

How to prevent blocked milk or breast ducts

Blocked milk ducts can be prevented by doing the following:

  • Wear a well-fitted bra. Tight clothes or ill-fitting bras might restrict the milk ducts within the breast.
  • Make sure your baby is in an effective position with a deep latch. If it’s already been checked but you’re still having difficulties, do seek more support. Often, even a good latch can be improved. Your midwife or health visitor should watch a whole feed or visit your local breastfeeding support group where a skilled breastfeeding supporter can do this.
  • Avoid long gaps between breastfeeds or expressing

(NHS, 2019a)

Milk blisters or blebs

Sometimes, a blocked duct is associated with a bleb or blister on the end of the nipple.  

These blisters look like the kind of friction blisters from wearing new shoes, or they can be filled with a little blood. They're likely to have been caused by your baby rubbing or compressing the nipple against their hard palate. If you have this kind of blister, do get support to improve positioning and attachment (Mohrbacher, 2010).

Milk blisters or blebs look like a flat patch of white on the nipple and can be really painful – although not always. Nobody really knows what causes them. It’s rare for blebs to occur in the first few days of breastfeeding but if your baby doesn’t attach well, they can appear early on (Mohrbacher, 2010).

Milk blisters that look like a slightly hardened plug can sometimes be removed by gently rubbing them with a flannel in the shower, or with a little bit of oil (Mohrbacher, 2010). Sometimes women say that the milk that had accumulated behind the blockage can flow and look a bit thickened (Mohrbacher, 2010).

If the bleb is caused by a thin layer of skin blocking one of the nipple openings, then opening it up can ease it. Don’t try this at home though as it could increase the chance of infection. Talk to your GP who might try using a sterilised needle to pierce the side or top of the blister and squeeze. This should unblock the duct and allow the milk to flow again. Make sure you keep the area clean while it’s healing (Mohrbacher, 2010).

Mastitis symptoms

If a blocked milk duct is not cleared, it can lead to mastitis. Mastitis is a common condition that causes inflammation and pain in the breast. It’s most common in the first three months after birth but it can happen anytime (NHS, 2019b).

Symptoms of mastitis may include:

  • A swollen, red or darker area (depending on skin colour), usually on one breast, that can feel hot and painful when you touch it.
  • A breast lump or a hard area.
  • Flu-like symptoms, such as aches, a fever, chills or tiredness.
  • A burning or radiating pain in your breast.
  • Nipple discharge, either white or with streaks of blood. 

(NHS, 2019b; La Leche League, 2016)

As well as trying the above suggestions, your GP might prescribe antibiotics (Jahanfar et al, 2013). For more information on continuing to breastfeed with, and treating, mastitis, take a look at this article.

This page was last reviewed in March 2021

Further information

We support all parents, however they feed their baby. If you have questions, concerns or need support, you can speak to a breastfeeding counsellor by calling our support line on 0300 330 0700, whether you are exclusively breastfeeding or using formula milk. Breastfeeding counsellors have had extensive training, will listen without judging or criticising and will offer relevant information and suggestions. You can also find more useful articles here.

You might find attending one of our Early Days groups helpful as they give you the opportunity to explore different approaches to important parenting issues with a qualified group leader and other new parents in your area.

Make friends with other parents-to-be and new parents in your local area for support and friendship by seeing what NCT activities are happening nearby.

National Breastfeeding Line (government funded): 0300 100 021.

Healthtalkonline.org: Managing Breastfeeding – dealing with difficult times.

Bonyata K. (2018) How do you treat a milk blister. Available from: https://kellymom.com/bf/concerns/mother/nipplebleb [Accessed 19th March 2021]

Jahanfar S, Ng CJ, Teng CL. (2013) Antibiotics for mastitis in breastfeeding women. Cochrane Database of Systematic Reviews. (2): CD005458. Available from: https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD005458.pub3/full [Accessed 19th March 2021]

La Leche League GB. (2016) Mastitis. Available from: https://www.laleche.org.uk/mastitis/ [Accessed 19th March 2021].

Mohrbacher N. (2010) Breastfeeding Answers Made Simple. Hale Publishing: London.

NHS Choices. (2019a) Breast pain and breastfeeding. Available from: https://www.nhs.uk/conditions/pregnancy-and-baby/breast-pain-and-breastfeeding/#blocked-breast-milk-ducts [Accessed 19th March 2021].

NHS Choices. (2019b) Mastitis. Available from: https://www.nhs.uk/conditions/mastitis/ [Accessed 19th March 2021].

NICE. (2015) Postnatal care. CG37. Available from: https://www.nice.org.uk/guidance/cg37/chapter/1-Recommendations#infant-feeding [Accessed 19th March 2021]

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