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Mastitis While Breastfeeding

Condition Basics

What is mastitis?

Mastitis is an inflammation of the breast. It occurs most often in people who are breastfeeding or pumping breastmilk. The inflammation occurs when the milk sacs in the breast are too full and cause swelling in the breast tissue.

Mastitis can leave you feeling very tired and run-down. If you have mastitis, it is important to keep breastfeeding, as stopping suddenly can make it worse. Treating mastitis right away helps prevent an infection from happening. Depending on your symptoms, your healthcare provider might prescribe antibiotics.

What causes it?

One of the main causes of mastitis is when your breasts become too full and make more milk than your baby needs. If this is happening, talk to your healthcare provider about ways to manage your breastmilk production.

What are the symptoms?

If you have mastitis, you may first notice:

  • A painful area on one breast. It may be red, warm to the touch, or both.
  • Chills, aches, and flu-like symptoms.
  • A fever.

Get help from your doctor or call Health Link at 811 if you have any of these symptoms.

If your symptoms are getting worse, the mastitis could be turning into an infection. This infection could lead to a breast abscess, which feels like a hard, painful lump.

How is it diagnosed?

Your doctor can usually diagnose mastitis based on your symptoms and by checking your affected breast. Tests usually aren't needed.

How is mastitis treated?

  • If you are exclusively breastfeeding, it is important to continue to breastfeed your baby regularly, following their cues to feed. Feed less often on the affected breast to avoid producing too much milk. If your baby does not feed from the affected breast, or it is too painful to feed, hand express to remove your milk. Avoid pumping if possible, as this could damage your breast and nipples. Try not to remove more milk than your baby needs.
  • If you are bottle feeding your breastmilk, continue to pump and feed your baby, following their cues to feed. Avoid pumping too much on the affected breast. Pump your breasts to comfort, they will feel softer.
  • Use a cold compress before feeding (like an ice pack or a bag of frozen vegetables wrapped in a cloth) on your breasts to help decrease your breast fullness and ease your pain. Don’t use the cold compress for longer than 20 minutes at a time to help prevent frostbite to your skin.
  • Talk with your healthcare provider about medicines you can use for pain and fever, such as ibuprofen and acetaminophen (Tylenol). Read and follow all instructions on the label.
  • Rest frequently and take care of yourself.
  • Avoid massaging your breasts. This could damage your breast tissue and increase the inflammation.

When should I call for help?

Call your doctor or 811 now, or seek immediate medical care, if:

  • Your symptoms do not get better within 24 hours.
  • Any part of your breast becomes increasingly red, painful, swollen, or hot.
  • Your fever continues or gets higher.
  • You have new chills or body aches.


You can sometimes get mastitis when bacteria enter the breast through a cracked or sore nipple. Taking these steps can help prevent mastitis.

  • Breastfeed regularly.

    Routine breastfeeding prevents bacteria from building up. If you know you'll go more than 4 hours without feeding your baby, arrange to pump.

  • Drink plenty of fluids.

    If you drink something while you breastfeed, it can help you stay hydrated.

  • Position yourself well, and position your baby's tummy to your tummy.

    When you and your baby are aligned, the baby can latch on to the areola, not just the nipple, and will be able to empty your breast.

  • Use different positions.

    This can help drain all areas of your breast. Try breastfeeding positions such as the Australian hold, the cradle hold, the cross-cradle hold, the football hold, and the side-lying position.

  • Alternate which breast you offer first.
  • Wear a bra that isn't too tight or restrictive.
  • Take care of your nipples.
    • Air-dry your nipples after you breastfeed. This can prevent irritation and cracking.
    • Use an over-the-counter lanolin-based cream on your nipples, such as Lansinoh.
    • Get help from your doctor or a lactation consultant for sore or cracked nipples.

Learn more



If you have mastitis, you may first notice:

  • A painful area on one breast. It may be red, warm to the touch, or both.
  • Chills, aches, and flu-like symptoms.
  • A fever.

These first symptoms may start after you have reopened a blocked milk duct.

Signs that mastitis is getting worse include swollen and painful lymph nodes in the armpit next to the infected breast, a fast heart rate, and flu-like symptoms that get worse.

The symptoms of mastitis most often appear within 4 to 6 weeks after childbirth.

In some cases, symptoms of mastitis may get worse and the breast forms a pocket of pus (abscess) in the infected area.

Thrush infection

Thrush (yeast infection) can occur in your baby's mouth and spread to your nipples and breast ducts. You may have a yeast infection if you have:

  • Symptoms of mastitis that don't go away with treatment.
  • Pain in the nipple area during and after you breastfeed.
  • Sharp breast pain between feedings.
  • Nipples that are flaky and dry or shiny.

If you have yeast infection symptoms, both your nipples and your baby's mouth should be checked for thrush.

Symptoms in infants include:

  • White patches on the inside of their cheeks.
  • Diaper rash.
  • Crying and going on and off the breast at feeds.

Thrush can also begin with a sudden start of pain or burning when breastfeeding has been going well without problems.

Symptoms of a breast abscess

Symptoms of a breast abscess include a breast lump that is hard and painful and a reddened area on the breast. You may also have flu-like symptoms that are getting worse.

Examinations and Tests

Your doctor can usually diagnose mastitis based on your symptoms and by checking your breasts. Tests usually aren't needed. But tests may be done to confirm a diagnosis. They may also be done to help guide treatment for other problems that can develop.

If you have an infection that isn't improving with treatment, your doctor may do a breast milk culture. To provide a sample for a culture, you will squeeze a small sample of milk from the affected breast onto a sterile swab. The culture results help your doctor confirm a diagnosis and find out the specific bacteria causing the infection.

Culture results may also be used to find out which antibiotic will work best for you.

Diagnosing a breast abscess

Your doctor can diagnose a breast abscess by checking your breast. If an abscess is too deep to check by touching it, your doctor may use a breast ultrasound. Ultrasound can also guide a needle to drain the abscess. A culture can then be done to identify the bacteria that are causing the abscess.

Learn more

Treatment Overview

Mastitis won't go away without treatment. Treating it right away helps keep the infection from quickly getting worse and usually eases symptoms after about 2 days. Delaying treatment can lead to an abscess, which can be harder to treat.

Treatment usually includes:

  • Taking antibiotics. They destroy the bacteria causing the infection.
  • Regularly emptying your breast by breastfeeding or pumping breast milk. This helps prevent more bacteria from collecting in the breast. It may shorten the time that the infection lasts. This includes varying your baby’s breastfeeding positions.
  • Self-care and taking acetaminophen to relieve pain, fever, or discomfort. You can rest as needed, drink plenty of fluids, and use an ice pack or warm compress on your breast.

It is best to keep breastfeeding your baby or pumping breast milk to feed your baby during illness and treatment. Your breast milk is safe for your baby to drink. Any bacteria in your milk will be destroyed by the baby's digestive juices.

Treating a breast abscess

Treatment for a breast abscess includes:

  • Draining the abscess. Healing can take 5 to 7 days.
  • Antibiotics that you take by mouth. They destroy the bacteria that are causing the infection. Antibiotics are given through a vein (intravenously) only in rare cases of severe infection.
  • Emptying the breast regularly and completely by breastfeeding or pumping. This is also very important for keeping a good milk supply.

Most people can keep breastfeeding with the affected breast while an abscess heals. With your doctor's approval, you can cover the abscess area with a light gauze dressing while your baby breastfeeds.

If you are told to stop breastfeeding your baby from the affected breast while an abscess heals, you can keep breastfeeding from the healthy breast. Be sure to pump or express milk from the infected breast regularly.

Learn more


Taking antibiotics and continuing to breastfeed or pump will help clear up mastitis. You can also take these steps to feel better.

  • Take an over-the-counter medicine.
    • Acetaminophen (such as Tylenol) can help with pain, fever, or discomfort.
    • You can also take ibuprofen (such as Advil) along with acetaminophen to reduce inflammation.
  • Rest as much as you can.
  • Use an ice pack or warm compress.

    Cold and heat can reduce pain in the sore breast.

    • If you use an ice pack, place it on the outside of your bra or clothes.
    • Do not put the ice on your bare skin.
  • Drink extra fluids.
  • Pump a little first if your breasts are very full (engorged).

    A breast that isn't quite so full can be easier for your baby to latch on to.

  • Wash off pus.

    If pus drains from your nipple, gently wash it off. Let your nipple air dry before you put your bra back on. You can also use a disposable breast pad to absorb the pus.

If you have trouble breastfeeding, you can get more help and support from your doctor or a lactation consultant.

Breastfeeding when you have mastitis

Antibiotics are used to treat mastitis. But breastfeeding is also a great way to prevent bacteria from collecting in the breast. It can also shorten the time that the infection lasts.

  • Breastfeed often.

    Your baby is the most efficient way to empty your breasts. And your milk is safe for your baby to drink. Your baby's digestive juices will destroy any bacteria in your milk.

    • Try to start on the sore side.
    • If you need to start on the other side, be sure to switch and empty the affected breast completely—until it is soft.
    • Vary your breastfeeding positions to be sure to empty your breasts.
    • If it's too painful to breastfeed at all, you can pump or express your milk.
  • Use a warm, wet face cloth on your sore breast.

    The heat from the face cloth can help increase milk flow.

    • Place the face cloth on the affected breast 15 minutes before you start to breastfeed.
    • Try this at least 3 times a day.
  • Massage the sore breast.

    This can also increase milk flow.

  • Use creams for sore or cracked nipples.

    Try a lanolin-based cream, such as Lansinoh.

  • Replace nursing pads often.

    Dry and clean pads are best.

Learn more



Adaptation Date: 9/5/2023

Adapted By: Alberta Health Services

Adaptation Reviewed By: Alberta Health Services

Adapted with permission from copyrighted materials from Healthwise, Incorporated (Healthwise). This information does not replace the advice of a doctor. Healthwise disclaims any warranty and is not responsible or liable for your use of this information. Your use of this information means that you agree to the Terms of Use. How this information was developed to help you make better health decisions.