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Mastitis and blocked milk ducts

Infected or blocked milk ducts can cause pain and discomfort when breastfeeding. A build-up of milk in the ducts can lead to inflammation of the breast tissue with some uncomfortable side effects. Fortunately, it is possible to cure the condition at home and with the right treatment it can clear up quickly.

By Mumsnet HQ | Last updated Apr 14, 2023


What is mastitis?

Mastitis is an infection caused when a blocked milk duct is not relieved. About 10% of breastfeeding mothers will suffer with mastitis at some point, but it can affect all new mothers (including those who have chosen to bottle feed) when your milk comes in after giving birth.

Mastitis is most common in your baby's first three months but occurs frequently in the second and third week once breastfeeding has become established. You can also be more susceptible to blocked ducts and mastitis when there are changes in your baby’s feeding pattern. Normally, only one breast is affected.

Mastitis that is left untreated can lead to infection requiring treatment by antibiotics. In the most severe cases, untreated mastitis can cause a breast abscess which would require an operation.

Read next: The best nipple shields for breastfeeding mothers, as tested by mums

What are the signs that I have blocked milk ducts?

Knowing how to spot a blocked milk duct will allow you to treat it and prevent the development of mastitis. You should look out for the following symptoms:

  • A red and swollen patch of skin
  • A painful, engorged lump in your breast
  • A white spot on your nipple known as a ‘bleb’ – this can look like a milk-filled blister and is due to an overgrowth of skin cells
  • The surface of your breast may be tender or hot to touch
  • A blocked duct will generally feel more painful before feeding with a noticeable feeling of relief after feeding
  • Milk supply may decrease temporarily as it can’t be released effectively.
  • You may notice ‘stringy’ milk when expressing, or grains of thickened milk.

How do I know if I have mastitis?

Blocked ducts that are treated promptly will usually clear within a couple of days without developing into mastitis. However, if you suspect that it may have developed into mastitis, you might also notice the following symptoms:

  • Intense pain, swelling and redness
  • Flu-like symptoms and a feeling of being tired and achy
  • A fever and chills with a high temperature over 38.5°C
  • Expressed milk may look lumpy, although it is still safe for your baby.

If you are not feeling better within 24 hours or you notice other symptoms such as pus or blood in your milk or red streaks on your breast, then you should see your GP, who may prescribe antibiotics.

How do I know if I have a breast abscess?

Breast abscesses only affect a small percentage of women who have had mastitis – roughly 3%. If your mastitis symptoms aren’t treated, then it’s possible they may led to a breast abscess. Even if you have been treated for mastitis, the persistence of symptoms can indicate that an abscess has developed alongside the mastitis. If you suspect an abscess, it is important that you seek medical advice straight away.

An abscess is a pus-filled hollow just beneath the skin that is surrounded by hard, inflamed tissue that feels like a lump. It’s caused by a bacterial infection. The presence of an abscess will usually be determined by an ultrasound. If it is an abscess, it will need draining. This can be done with a needle if it's small, or through a small cut, if it's large. Either way you’ll usually be given a local anaesthetic before the procedure.

Mumsnetters who've had abscesses strongly recommend insisting on a referral to a breast-specialist consultant and, if you want to continue breastfeeding, seeking advice from a breastfeeding-specialist midwife.

Most women who have breast abscesses or severe mastitis continue to breastfeed as normal following treatment.

“I had an abscess with my first son as the result of mismanaged mastitis. I was gutted that it had all gone so wrong and it took a long time to get over it. I worried about what it would be like with a second child but he’s now 13 months and I’m still breastfeeding him. It’s been a completely different experience and I have no idea when I'll stop feeding him as it’s all so easy. No mastitis at all this time, not even a sore nipple.”

What causes blocked milk ducts and mastitis?

Blocked ducts are caused by a build-up of milk that obstructs the flow to the nipple. This build-up can be caused by a variety of factors.

  • Poor milk drainage is the most common reason for blocked ducts. This can either be caused by not feeding your baby frequently enough or because you’ve dropped a feed.
  • If your baby’s latch or position is not right, it can prevent her from feeding properly and may mean she doesn’t empty your breast fully.
  • You could have an oversupply of milk. Mums who produce an abundance of milk will be used to engorged, leaky breasts but oversupply can also lead to blocked ducts as it becomes more difficult for your baby to drain your breasts completely.
  • Infection. You are more susceptible to infection if you have cracked nipples or if your immune system has been compromised by another illness.
  • Pressure on your breasts such as an ill-fitting bra or tight clothing can reduce the flow of milk. Lying on your front for long periods of time can also affect milk flow.

How do you clear a blocked milk duct?

breastfeeding latch

The pain, discomfort and sheer sight of lumpy milk may be enough to tempt you to stop breastfeeding but feeding frequently is actually the best way to relieve a blocked duct. You should try to feed at least every two hours and continue to do so throughout the night. That might not sound appealing but it will be worth it to sort the problem out.

Your milk will flow slowly at first but eventually the near-constant flow of milk will clear the blockage. If you are unable to breastfeed, you should express instead to keep the milk flowing.

You should treat mastitis in the same way.

Other ways to clear a blocked duct:

  • When feeding your baby, offer the affected breast first and ensure she drains this breast completely before offering your other breast. Avoid pulling her off your breast too quickly.
  • Change your feeding position. If you can get your baby’s chin to point towards the blocked duct this will ensure that milk flows through the affected duct and you may even be able to use her chin to massage the lump while she feeds.
  • Massage the affected area. Gently massaging the lump before and during feeding can help. Some mums find that it helps to use a comb to massage down towards the nipple. We promise this is not as painful as it sounds but do be careful to stop before you get to the actual nipple!
  • Set your nipple free – take off your bra when you can, and when you do wear one, try to avoid underwired bras or any tight clothing that might apply pressure or restrict movement.
  • Apply heat to your breast. Have a hot shower or bath and gently massage the affected area. Or you could apply a warm flannel, hot water bottle or heat pad. It’s a good idea to feed your baby or express some milk immediately after.
  • If your nipples are cracked, treat them with a lanolin-based cream or another remedy to avoid infection.
What really helped me was a few leaves of chilled white cabbage in my bra when I went to bed.
  • Cabbage leaves applied to your breasts sounds crazy but lots of mums swear it works. Just stick one in each of your cups and change them when they get a bit limp and sweaty.
  • Rest as much as you can and drink plenty of fluids.
  • If the pain is unbearable, you can take a painkiller such as ibuprofen or paracetamol. Some medicines, such as aspirin, are not safe to take while breastfeeding – so make sure you know what you're taking is OK.

Should I stop breastfeeding while I have mastitis?

No. Although painful, feeding frequently can help to clear the blockage. If you find it very painful, try to apply heat to the affected area before feeding or massage while feeding to help the milk to flow freely.

Will mastitis affect my baby?

No. While it is painful for you, it does not affect the quality of your milk except to make it taste slightly saltier.

How do you avoid getting mastitis?

When it comes to mastitis, prevention is better than cure. Adopting certain feeding practices from the outset will help to prevent blocked ducts or a recurrence of mastitis.

Make sure you are finishing every feed. Let the baby suckle until they have finished every last drop before switching sides or stopping the feed.
  • Breastfeed regularly. Don’t be tempted to skip or drop a feed. Doing so can cause a build-up of milk that leads to blocked ducts. If you are considering mixed feeding, then make sure to express in between feeds.
  • Check that your baby is latched on correctly. If your baby has a poor latch, she won’t be able to feed properly and won’t drain your breasts fully. If you are concerned about her latch, ask your health visitor to observe you feeding.
  • Get your position right. Remember that your baby’s tummy should be facing yours. This will ensure she doesn’t have to turn her head and is comfortable to feed for as long as she needs to. Again, your health visitor or local breastfeeding group can provide support and advice on positioning.
  • Use different positions when feeding to stimulate all of your milk ducts.
  • If your baby is not sucking properly during feeds, breast compressions can help to keep the milk flowing during feeding.
  • Treat engorgement as soon as it occurs.
  • Make sure that your bra fits well and avoid underwired bras, which can increase pressure on your milk ducts.
  • When changing your baby’s feeding schedule, such as when introducing mixed feeding or when weaning, do so gradually to allow your milk supply time to adjust.
  • Some Mumsnetters find that taking lecithin as a supplement helps to prevent recurring mastitis.

Mumsnetters' top tips for treating blocked ducts

“I managed to clear a duct while I was expressing. I used LOADS of warm compresses and got my son to feed the opposite way to normal on the blocked breast.”

“Get the Lansinoh Therapearl Gel Pads. AMAZING. Probably saved my breastfeeding during mastitis. Microwave them and apply to boob.”

“One thing that worked for me was using something that vibrates, like a toothbrush, to massage the lump.”

“I've had a few very stubborn blocks. I tried baths, expressing, hot compresses, ibuprofen. But what really helped was a few leaves of chilled white cabbage in my vest/bra when I went to bed. For some reason it seemed to soften the block and help it clear.”

“I find that pumping and feeding on the affected side, drinking lots and lots of fluids, a hot water bottle and massage will usually shift it after 24 hrs. If the redness spreads or you start feeling crappy get some antibiotics.”

“What worked for me was a bowl of water as hot as I could stand. Lean over it so your breast is submerged. Then massage and manually express into the water. You'll need to be quite firm on the hard areas, working towards the nipple. Then get little one to feed right after.”

“A top tip I read somewhere was to pour hot water on a nappy and use it as a heat pad as they hold heat for longer than a flannel.”

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