What Is Mastitis?

Mother in pain breastfeeding her baby
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Mastitis is swelling or inflammation of the breast that may be accompanied by an infection. In fact, it's a common breastfeeding problem that potentially affects as many as 33% of nursing mothers.

Although mastitis can occur any time you're breastfeeding, it's more likely to happen within the first six months. When combined with the pressures of caring for a newborn and the pain that sometimes comes with the condition, many women consider giving up breastfeeding.

However, continuing to breastfeed while having mastitis can actually help clear the infection. Even though mastitis is discouraging, it is easily treated.

Mastitis Symptoms

Usually, mastitis begins with a painful area in one breast that may be tender, red, warm, and swollen. It also can cause you to feel very tired and run-down. Here are some additional signs and symptoms of mastitis.

  • Body aches
  • Chills
  • Fatigue
  • Fever
  • Flu-like symptoms
  • Nausea
  • Pain

Signs that the mastitis may be getting worse include painful, swollen lymph nodes in the armpit near the infected breast, a fast heart rate, and worsening flu-like symptoms. If left untreated, mastitis can even lead to a breast abscess.


You can get mastitis from an infection. Bacteria or other microorganisms can enter your body from cracked nipples or any opening in your skin. Once bacteria find their way into your breasts, they can cause an infection.

Another way you can get mastitis is by not removing the breast milk from your breasts regularly and efficiently. Breast milk may not drain from your breasts well when:

Breast engorgement and plugged milk ducts are two other common breastfeeding concerns that can lead to mastitis. Mastitis also can be caused by: 

  • A tight bra, an underwire bra, or a nursing bra that does not fit properly
  • Improper nursing technique
  • Strenuous exercise, especially of the upper body
  • Excessive tiredness or stress
  • Poor nutrition
  • Smoking


If you think you have mastitis, notify your doctor as soon as possible. Your doctor will examine your breasts and come up with a treatment plan.

Most of the time, mastitis is diagnosed with an examination and additional tests are not needed. However, if the mastitis doesn't clear up or continues to get worse, your doctor may order the following tests.

  • Breastmilk culture: If your infection is severe, occurred in the hospital, or isn't responding to antibiotics, your doctor may order a culture.
  • Ultrasound: Sometimes doctors will order an ultrasound if your condition doesn't improve within 48 to 72 hours.
  • Blood cultures: If your breast redness continues to worsen and your vital signs become unstable, the doctor may order a blood culture.


Your doctor may prescribe an antibiotic, but don't worry that the antibiotic will harm your baby. Your doctor will prescribe one that's safe to use while you're breastfeeding. Medication, rest, and the regular removal of milk from your breasts will help you to recover more quickly.

With immediate treatment, you should begin to feel better within 48 hours. If you aren't feeling better, or your condition is worsening, be sure to contact your doctor right away.

Breastfeeding Implications

In most cases, you don't have to stop breastfeeding if you have mastitis. It's safe to breastfeed while you have mastitis, and it will not harm your baby or interfere with the healing of your breasts. 

In fact, the best way to treat mastitis is to keep the breast milk flowing from your breasts by breastfeeding every two hours. If you cannot breastfeed, use a breast pump or hand express the milk from your breasts every few hours.

Keep in mind, though, that your breast milk changes during mastitis as the levels of lactoferrin rise. Sodium and chloride levels also go up, which can make your breast milk taste salty, while your lactose levels decrease.

Some infants don't like the change in flavor of breast milk and may refuse to breastfeed on the side with the mastitis. 

If your baby is refusing to nurse, try supplementing with previously stored breast milk. You also should continue to pump breast milk at regular intervals to help maintain your milk supply.

Keep offering your breast to your little one as well. As your infection clears in a day or so, your breast milk will return to its pre-mastitis taste and your nursing relationship can continue.


Mastitis can be painful in the beginning and cause you to feel like you have the flu. For this reason, it's important to rest, practice good self-care, and manage your pain. Follow these suggestions and guidelines for coping with mastitis.

Breastfeeding Tips

Although you may be anxious about breastfeeding when you have a breast infection like mastitis, or it may be uncomfortable, continuing to nurse your little one is the best route to take. These tips can help make it easier.

  • Start breastfeeding on the swollen side if you can. Your baby's suck will be stronger at the beginning of a feeding, which may help remove breast milk from any clogged areas in your breast.
  • Place a warm compress on your breast or take a warm shower before breastfeeding to help with your let-down reflex and the flow of breast milk.
  • Move your baby to the other breast if the mastitis is painful and interfering with your let-down reflex. Once the let-down begins, put the baby back on the painful breast.
  • Use correct positioning and make sure that your baby is latching on properly. With a good latch, you're less likely to develop sore, cracked nipples, and your baby can remove the milk from your breasts and drain your breasts much better.
  • Pay attention to your baby's latch. Try to latch your baby on with their nose or chin pointing toward the clogged area of your breast. This position will help to remove the breast milk from that particular spot.
  • Change your breastfeeding positions each time you breastfeed to help empty different areas of your breasts.
  • Pump or hand express after breastfeeding to remove even more breast milk.


When you have mastitis, it's important that you take good care of yourself. Try not to push yourself or do too much. Here are some reminders of how to care for yourself while your body recovers.

  • Get plenty of rest.
  • Drink plenty of fluids, especially water.
  • Eat a healthy, balanced diet.
  • Massage the swollen, tender area to help loosen any breast milk that's clogged there.
  • Start massaging the breast at the affected area and work your way up to the nipple.
  • Ask for help at home if you have older children.

Pain Relief

There's no denying that mastitis is a painful condition, especially if your infection is particularly severe. For this reason, it's important to take steps to reduce your pain level and provide as much comfort as you can.

  • Use a cold compress or cold cabbage leaves after each feeding to relieve pain and swelling.
  • Ask your doctor if you can take a pain reliever like Tylenol (acetaminophen) or Motrin (ibuprofen). These over-the-counter medications can decrease pain and swelling.
  • Follow all the directions on your prescriptions and take them for as long as they're prescribed to prevent the infection from coming back.


While you can’t completely prevent mastitis, there are steps you can take to try to lower your risk of developing it. Follow these guidelines to reduce the risk of developing mastitis.

  • Use proper breastfeeding techniques: When your baby is correctly latched on, they can remove your breast milk better, and they are less likely to cause damage to your nipples.
  • Alternate feeding positions: Different nursing positions drain different areas of the breast, which helps to prevent breast milk from getting clogged in certain areas.
  • Change breast pads often: If you wear breast pads for leaking, make sure to change them frequently to stop the growth of bacteria. Wet breast pads also can break down the skin on your nipples, creating an entrance for infection.
  • Prevent your breasts from becoming engorged: Nurse your baby, pump, or hand express your breast milk often to prevent breast engorgement and plugged milk ducts, which can lead to mastitis.
  • Avoid wearing tight bras: Tight bras or anything that confines, restricts, or puts pressure on your breasts can cause a breast infection.
  • Wean your baby gradually: Abrupt weaning can cause breast engorgement. But, if you wean your baby slowly, your milk supply will gradually go down, lessening the chance for engorgement, plugged ducts, and mastitis.
  • Take care of yourself: Try to eat enough calories, stay hydrated, and get enough rest. Stress and fatigue are risk factors for mastitis.


If your symptoms do not get better within 24 to 48 hours, it's important to contact your doctor. A delay in treatment can lead to complications such as early weaning, breast abscess, or thrush.

Early Weaning

The development of mastitis may cause some women to consider weaning. Nursing with mastitis is safe, and it helps to clear the infection, so it's not necessary to stop breastfeeding. In fact, the sudden end of breastfeeding can make mastitis worse, and it's more likely to lead to an abscess.

Breast Abscess

An abscess is a tender, fluid-filled lump that can form in your breast as a result of mastitis. If you develop an abscess, your doctor may need to remove the fluid with a needle, or you may have to have minor surgery.


Thrush is a fungal or yeast infection. Yeast is naturally present on and in our bodies, but when it overgrows or moves to a place it shouldn't be, it can become a problem. Thrush can cause a breast infection by getting into the breast through damaged nipples, but it can also develop as a result of mastitis.

The use of antibiotics to treat mastitis can lead to an overgrowth of yeast. When this happens, you can develop a yeast infection that causes red, burning nipples and breast pain. You also may see white patches or redness in your baby’s mouth.

If you see thrush on your nipples or in your child’s mouth, call the doctor. Both you and your child will need treatment with an anti-fungal medication. And, because yeast spreads quickly and is difficult to get rid of, it's possible that other family members may need to be treated as well.

A Word From Verywell

Although mastitis is a common breastfeeding problem, this doesn't make it any less discouraging or painful to deal with. The good news is, with early treatment, you should notice improvement within 24 to 48 hours.

If, for some reason, you don't notice improvement or you start feeling worse, contact your doctor. Mastitis is not a condition you want ignore or put off treating. You and your baby will feel much better and will be able to return to a pain-free nursing experience the sooner you seek treatment.

8 Sources
Verywell Family uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Donna Murray, RN, BSN
Donna Murray, RN, BSN has a Bachelor of Science in Nursing from Rutgers University and is a current member of Sigma Theta Tau, the Honor Society of Nursing.