Everything New Moms Need to Know About Mastitis

Everything you need to know about mastitis, from causes and prevention to treatments.

woman breastfeeding baby while suffering from mastitis
Photo: Paulo Sousa / EyeEm/Getty

Laura Donovan, 32, was close to three weeks postpartum and breastfeeding her first son when she started experiencing a fever, nausea, and — despite 85°F Southern California weather — cold chills. "I had no appetite, went to bed shivering, and woke up drenched in sweat," says Donovan. "It was hell. I was so engorged, it was like I was carrying bags of rocks on my chest. I could spend an hour hand expressing the milk and still feel totally full and uncomfortable."

As a first-time mom who had never nursed an infant before, Donovan didn't realize that she was experiencing mastitis, a common breastfeeding complication that can be incredibly painful and often requires professional medical attention. Around one in 10 breastfeeding women in the U.S. (as well as nursing trans men and non-binary lactating parents) get mastitis over the course of their nursing journey, according to the American Family Physician Journal, yet, many women don't know about it until they're already suffering. Here are the basics.

What Is Mastitis?

"Mastitis, in short, is an inflammation of the breast that can be caused by blockage or infection," says Rebecca Koyf, R.L.C., C.L.C., IBCLC, a lactation consultant practicing at New York Lactation Care Inc. "It's important to note, however, that although mastitis usually affects women who are breastfeeding, it can also occur in women who aren't breastfeeding as well as in men." (

The main cause of mastitis is a clogged milk duct, which can happen if a breast doesn't completely empty at feedings, causing milk to back up and leading infection, according to the Mayo Clinic. Mastitis can also be caused by a bacteria entering the breast and causing an infection, often because bacteria in a baby's mouth enters the breast via a crack or cut.

As Donovan experienced, fever, chills, and feeling generally ill are all common symptoms of mastitis. Other symptoms include breast tenderness, breast swelling, the breast feeling warm to the touch, pain or burning while breastfeeding, lumps in the breast, and the skin of the breast turning red and/or inflamed. Of course, not every case of mastitis is as severe as Donavan's; in most cases, breastfeeding can continue during mastitis, and rarely does mastitis occur in both breasts at the same time.

Like many aspects of postpartum life — be it bleeding, inflammation, or the mental health ramifications of pregnancy, labor, and delivery — mastitis is rarely discussed unless you're in the throes of it or have previously experienced it. Studies have shown that inadequate breastfeeding education and information about possible breastfeeding issues such as mastitis can actually make nursing more difficult for lactating parents.

"You don't know until it happens to you," says Donovan. "Mastitis was the worst medical experience of my life, and I've now had two C-sections."

Can You Prevent Mastitis?

If you're nursing or pumping regularly, there are steps you can take to help reduce your chances of getting mastitis.

"Avoid tight-fitting clothes and going long stretches without moving the milk, [via either] pumping or nursing," says lactation consultant Thaisa Lemos, Ph.D., C.L.C. IBCLC. (How long you go between feeds will depend on how old your baby is. To avoid mastitis, make sure you're emptying the breast fully and switching sides and breastfeeding positions.)

Also, keep an eye out for clogged milk ducts. It will feel like a lump in the breast (a common reason why breast cancer is more difficult to catch in breastfeeding women). "If you notice a clog, try to remove the clog as soon as possible," says Lemos. To do so, "breast massages are good, but people tend to put too much pressure and end up pushing the clog deeper into the tissue, making it worse. If you don't know how much pressure to use, using an electric toothbrush — or a vibrator — on the breast to loosen up the clog, and immediately nursing or pumping to drain the clog is the way to go."

While mastitis certainly doesn't discriminate, there are some things that can increase your chances of experiencing mastitis, including smoking or having nipple piercings or cracked nipples. "A history of mastitis, breast surgery or injury to the breast, compromised immune system, stress, fatigue, and anemia could [also] make a person more susceptible to mastitis," adds Koyf.

Most new moms do feel fatigued and stressed, so it can seem like a cruel joke that both can increase the risk of mastitis. Along with the mental health ramifications of sleep deprivation (studies have shown inadquate sleep can increase the risk of postpartum depression), this is yet another reason why moms need to prioritize their sleep as much as possible.

How Does Mastitis Affect Breastfeeding?

As mentioned, mastitis can cause a range of symptoms, all of which can make nursing uncomfortable and difficult. If mastitis complicates nursing to the point where you no longer want to continue, remember that it's ultimately your body and your choice in how you feed your baby. "The first impact [of mastitis is] making the nursing parent not-well enough to have the energy to nurse," says Lemos. "Then, if it's painful, the nursing parent will be less likely to nurse, which then eventually negatively impacts the supply."

But having mastitis does not automatically mean you have to stop or cut short your breastfeeding journey. "Many moms feel that they cannot nurse if they have mastitis, or if they're taking antibiotics [as a treatment for it]," says Dr. Lemos. "In reality, nursing during mastitis is safe and recommended. Babies are usually much more efficient at removing milk than a breast pump. Milk supply might dip temporarily during and after mastitis, but with frequent milk removal supply recovers and comes back up."

How Do You Treat Mastitis?

Seeing a doc for treatment can help you overcome mastitis as quickly as possible.

"There are two lines of treatment that need to be conducted in combination," says Lemos. "One, a doctor will treat the infection. Often people need antibiotics, or at least something to help reduce the pain and fever. Two, a lactation consultant helps to identify and correct the original cause of the infection: adjusting the baby's latch and positions to avoid nipple wounds, teaching how to keep milk moving adequately, and teaching how to avoid clogged cuts and supply issues. But the bottom line is that you address the symptoms with a physician and you keep the milk flowing."

It's recommended that you continue breastfeeding (if you want to) while you treat mastitis, even if you are prescribed antibiotics. The medications will not harm your baby, so there's no reason to pump and dump or switch to formula if you don't want to.

What New and Future Moms Should Know

Breastfeeding can be a peaceful, nourishing act between parent and infant that brings about deep feelings of connection, bonding, and love (that's why some people are even getting breastfeeding tattoos). But it can also be frustrating, complicated, and painful. Mastitis is one of those such complications, but the more you know about this common nursing outcome the more you can be better equipped to handle both the physical and mental ramifications. Because, even though it's common, mastitis can bring about feelings of shame, stigma, and self-doubt. Studies have shown that women who stop breastfeeding earlier than they initially intended can experience negative mental health outcomes, and moms who don't particularly enjoy breastfeeding (especially if it's painful due to mastitis) can feel as though something is "wrong" with them or that they have somehow failed.

That was certainly the case for Meghan Atkins, 36, who had mastitis when her son was 2, 3, and 5 weeks old and in the midst of the ongoing COVID-19 pandemic. Because of her mastitis symptoms, she was initially worried she had contracted coronavirus. But once those fears passed and she was prescribed antibiotics by her physician, she was left wondering if she had done anything wrong that may have caused the mastitis in the first place.

"I had breastfed all three of my older children without experiencing mastitis even once," says Atkins. "So I began to feel very defeated and frustrated, along with sad and angry. Also shameful, like I was doing something wrong. I also felt like nursing had become 'work' rather than a sweet moment to sit in a quiet spot — just my new baby and I — and bond. Mastitis really messed with me emotionally during an already vulnerable and emotional time being only a few weeks postpartum."

When as many as 20 percent of new moms in the U.S. experience postpartum depression, and studies have suggested that breastfeeding difficulties can increase a person's risk of experiencing postpartum depression and other negative mental health outcomes, being knowledgeable about mastitis, its causes, and how it can make breastfeeding challenging can help you navigate this complication.

"Getting mastitis initially turned me off to breastfeeding," says Donovan. "Then I got pregnant again, right before the pandemic hit, and saw women in my local mom groups on Facebook complain that they couldn't find formula anywhere due to all the panic buying. So I decided to give nursing another try with my second child, and it's going great. I think it's going well this time around because I knew going into it how to prevent mastitis."

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