Mastitis - La Leche League GB

Mastitis means ‘inflammation of the breast’, and includes a wide range of symptoms, from a small, tender area (often called a ‘blocked duct’), through to severe infection and even abscess.

If you have any signs of breast inflammation, prompt action is important to help relieve discomfort and stop it getting worse. It’s also necessary to address any underlying causes.

Mastitis is not always caused by infection. However, when milk leaks into the breast tissue, your body can respond as if infection were present – with inflammation. As well as having signs of swelling in one or both breasts, you might feel ill, with a fever or flu-like symptoms.

Your commitment to breastfeeding your baby can be truly tested at times like this, especially when putting your baby to the breast may be the last thing you feel like doing. However, continuing to breastfeed (or expressing your milk) as normal is part of the solution, and stopping breastfeeding suddenly is likely to make the problem worse.

Except in very rare circumstances, your milk is safe for your baby, and medications for mastitis are safe to take while breastfeeding.

Signs of mastitis
What you can do
Keep breastfeeding
Causes of mastitis
Avoiding future problems
Milk blisters (blebs)
Expressing blockages
Cracked nipples
Breast infections
Breast abscess
Breast lumps
Recovering from mastitis

Signs of mastitis (you might have one or more)

One or more hard, sore lumps in your breast.
The skin on your breast is warmer than usual.
Feeling achy, and run down.
Feeling feverish.
You might also notice changes in colour: redness or darkening, depending on your skin tone. Colour changes on the breast are most obvious in lighter skin tones, but even if there’s nothing to see, you might still have mastitis.

What you can do

- Continue feeding your baby as often as they want to feed (including at night-time). It is not necessary to feed more often than usual from the affected breast, or try to remove every available drop of milk – this can increase milk production, and may make the problem worse. (See How Milk Production Works.) Try to avoid your breasts becoming overfull by encouraging your baby to nurse often enough to leave your breast feeling soft and comfortable. If they are unwilling to nurse, gently hand express or pump enough milk to get the breast comfortably soft.
- Ensure your baby is well attached at the breast when they feed. It may be helpful to try some different positions from usual, to see if this helps drain different areas of the breast. If you’re not confident about getting your baby deeply attached at the breast, contact an LLL Leader or your local feeding supporter. See Comfortable Breastfeeding for more information on getting a deep latch.
- Use cold to reduce the swelling. You could use an ice pack or crushed ice wrapped in a cloth, a bag of peas wrapped in a towel, or a clean cloth wrung out in very cold water. Swap it every 20-30 minutes, when it’s no longer cold. Older advice often suggested using heat, but we now know that this can make the inflammation worse.
- It’s important not to handle your breast roughly, as this can make swelling worse (and will hurt!). You can’t move milk by force. Only touch the breast firmly if it helps you remove milk while feeding or expressing, or if it feels good. Use very light touch, as you would when applying cream to your skin.
- Consider taking an anti-inflammatory medication such as ibuprofen, if you are able to, to reduce the inflammation. Ibuprofen is compatible with breastfeeding, but check with your pharmacy about the safety of other anti-inflammatory painkillers. If it’s difficult to remove milk because the breast is so hard and tight, try taking a dose (and applying a cold compress) about half an hour beforehand, to get the swelling down first.
- Rest. While you have mastitis, you need to be taken care of as if you are properly unwell (even if symptoms are mild), and rest as much as you can. Inflammation is taxing on your whole body, and you need to heal. It’s common to come down with mastitis if you’re feeling under the weather or doing more than usual. If it’s safe to do so, go to bed with your baby, or keep your baby close to your bed – and stay there as much as you can. See our tips on Safer Sleep & the Breastfed Baby. Don’t be tempted to do too much too soon. It’s common to feel low and tearful when you have mastitis – as well as the discomfort, and maybe feeling unwell, inflammation can also affect your mood. Once you get the swelling under control, you will probably feel much better. If you’re really not feeling like yourself, talk to supportive family or friends, your health visitor or GP – there is lots of help available.
- Drink plenty of fluids.

If

You don’t start to feel better after 24-48 hours of using the self-help measures above;
You have pus or blood in your milk;
You see streaks on your breast from areola to underarm or if your breast shows further changes in colour (e.g. the size of a red or darkened area is increasing)
Your breast gets hotter or more swollen;
You see signs of infection in a nipple wound, such as crustiness, yellow ooze, change in colour, size or shape of the nipple;
Your temperature increases to 38.4°C or more.

Then continue following the previous steps, and also

Contact your GP or call NHS 111. You may need antibiotics. Even if mastitis is not caused by infection, they are effective, probably because they reduce inflammation.
Take the full course of any prescribed medication. NHS mastitis guidelines say that if antibiotics are needed for mastitis, a 10-14 day course is appropriate.

Keep breastfeeding

It’s important to keep milk flowing through the affected breast, while you’re treating mastitis.

Weaning from the affected breast is sometimes suggested, but it is not necessary, and is likely to make matters worse. Antibodies in your milk will help protect your baby from any infection.

The affected breast may produce less milk for a few days, and your milk may taste slightly different. Encourage your baby to feed as normal. Occasionally, a baby will refuse a breast with mastitis – if this happens, keep the milk flowing by expressing as often as you need to, to keep the breast comfortable. Once the mastitis has resolved, milk production usually bounces quickly back to normal.

Causes of mastitis

It’s important to address any underlying causes of mastitis, to help prevent future episodes. Mastitis can be caused by anything that limits or prevents milk flowing through the breast, including:

A baby who is not breastfeeding effectively.
Missed, shortened or irregular feeds or expressions. (For example, using a dummy may make early feeding cues easy to miss.)
Anything that puts pressure on the breast, such as a bra or other clothing that is too tight, a seatbelt or bag strap, a baby carrier, or even lying on your front.
Occasionally, a tiny white or yellow ‘milk blister’ (also known as a ‘bleb’) forms on the end of the nipple, and can block milk in part of the breast. See below.

Mastitis is more likely to occur if you’re extra busy, or when others in the family are unwell. Changes in routine, holidays, visitors or family events – when you are busy or your baby is distracted – can also make mastitis more likely. Some mothers are more susceptible than others.

If you’ve had breast surgery, breast injury or have a breast abnormality, these may increase the risk too. Underlying health issues can also make mastitis more likely: if you’re anaemic, for example, or have low thyroid, and are feeling exhausted.

An LLL Leader can help you identify likely causes of mastitis if you wish.

Avoiding future problems

Breastfeed your baby (or express your milk) frequently, avoiding long gaps, day and night. Sleeping close to your baby can make night feeds easier. See Safer Sleep and the breastfed baby.
Check that all areas of your breasts feel soft and comfortable after feeds. If any area of your breast is hard and uncomfortable, take action promptly: try a different position, or gently massage as you breastfeed.
Take extra care of yourself during holidays, special occasions and when family members are ill.

Milk blisters (‘blebs’)

Sometimes a mother gets one or more white or yellowish spots, called milk blisters or ‘blebs’, on the tip of her nipple. A milk blister might show up more clearly after a feed, or if you gently compress the nipple. Thickened milk may block milk flow near the opening of the nipple, or a thin layer of skin may block the milk duct.

Blebs can sometimes cause mastitis. A bleb that does not hurt or block milk may resolve on its own over several weeks – there’s no need to do anything about it.

If it is painful, or is blocking milk in part of the breast:

Apply moist heat using warm compresses, and then feed your baby — nursing may open the blister.
Soak the nipple in warm water.
Wear a cotton ball soaked in olive oil in your bra to soften the skin and then attempt to peel away the thickened layer of skin.
Try using a mild steroid cream on the surface of the bleb to thin the skin. Then, compress the nipple behind the blockage to try and express the blockage. Sometimes it is possible to express a thickened string of milk, which helps open the duct and keep it open. Work back from the nipple to make sure there isn’t a blockage further back. See above: Expressing Blockages.
If the ideas listed above don’t help, a last resort is to open the milk blister. Some experts say that repeated opening of the skin could make the situation worse, however some mothers have found that removing the top layer of skin over the bleb enables the blockage to come out. If you decide to open the milk blister, you could try it yourself with a sterilised needle or ask a health care professional to help you. Take care to prevent infection by washing your nipple with mild soapy water.

Expressing blockages

Sometimes, when gently massaging a ‘blocked duct’, you may express the coagulated milk responsible for the blockage. It may look like a crystal, a grain of sand, or even a strand of spaghetti, and it may be accompanied by a little particularly thick milk or mucus. If your baby clears the blockage when feeding, this will not harm them.

Cracked nipples

Sore, cracked nipples may increase the risk of a breast infection. Good wound hygiene is important, along with addressing underlying causes of nipple damage. Always wash your hands before touching a damaged nipple. Washing your nipples gently once a day with mild soap and water may be helpful, while you have a wound.

Moist wound healing, for example using a hydrogel pad, has been shown to speed up the healing of cracked nipples. You could also ask your doctor about using a medicated ointment to promote wound healing.

Breast infections

This is the more severe end of the spectrum of mastitis.

You are more likely to develop a breast infection if you stop removing milk from a breast that already has mastitis.

A full course of antibiotics is needed to clear a breast infection. Most antibiotics are compatible with breastfeeding. Stopping antibiotics early leaves you vulnerable to further infection.

Most, but not all, breast infections are caused by Staphylococcus Aureus bacteria. Some strains of bacteria e.g. MRSA have become resistant to certain antibiotics. Let your doctor know if you have, or have had, MRSA, as this may help with prescribing appropriate treatment.

Repeated use of ineffective antibiotics increases the risk of a breast abscess. If a breast infection recurs, and especially if you took a full course of antibiotics, discuss this with your doctor. An alternative antibiotic may be needed, and a culture of your milk and your baby’s throat may be helpful. If you need treatment for MRSA you can continue to breastfeed.

Sensible hygiene precautions include hand washing (including your baby’s hands), using disposable breast pads and thorough cleansing of pump parts and other items that are in contact with your nipples, e.g. nipple shields.

Breast abscess

A breast abscess is an uncommon complication of mastitis, usually because it was not adequately treated. It is a localised infection containing pus. Abscess can be diagnosed by ultrasound and needs immediate treatment by surgical drainage or aspiration of the breast. Usually, the abscess will need to be drained multiple times.

To avoid breast tissue being damaged unnecessarily, ask for the incision to be made:

As far from the nipple as possible,
From nipple to chest, rather than around the breast.

The fluid should be cultured to identify the infection, so you receive appropriate antibiotics. You can continue to breastfeed from both breasts. If the affected breast is too painful, or the incision is close to your nipple, you may need to hand express for a day or two. Keeping your milk flowing will help your breast heal.

Breast lumps

Many women worry that they may have cancer if they discover a breast lump. Studies have shown that breastfeeding reduces a mother’s risk of breast cancer.

However, a lump that does not go away after a week, or recurs in the same place despite careful treatment for a blocked duct, needs checking. In many cases breast lumps are benign tumours (fibromas) or milk-filled cysts (galactoceles), which can be diagnosed and treated whilst you continue to breastfeed. It is very rare for a lump to be a sign of cancer. But do consult your doctor, especially if the lump continues to grow, does not move, or is firm and hard, and if there is dimpling of the skin.

Recovering from mastitis

It may take a little time and persistence to deal with mastitis and enjoy comfortable feeds once more. Sometimes it takes time to find the right medication for an infection. Alongside any medication, being creative about making time to rest and recuperate can make a great deal of difference and help to prevent mastitis recurring.

Written by Karen Butler and mothers of LLLGB. Thanks to Justice Reilly and Jayne Joyce.

Last updated May 2023