Overview of Mastitis

Mastitis is an inflammatory condition in the breast typically caused by overproduction of milk and disruption to the bacterial balance in the breast. It’s a fairly common condition, affecting between 2-30% of breastfeeding people, and it’s a frequent reason that parents wean earlier than they hoped to.

If you’ve ever experienced mastitis, you know how painful and uncomfortable it can be, and you likely have questions about what causes the condition, how to tell you if you have it, and the best ways to treat and prevent it.

Let’s take a deep dive into mastitis during breastfeeding, and answer parents’ most common questions.

What Causes Mastitis?

According to new guidelines put forth from the Academy of Breastfeeding Medicine (ABM), mastitis has two main causes. It results from hyperlactation (an overproduction of milk), combined with changes to the breast microbiome, which refers to the bacterial makeup of the mammary glands.

Engorgement of the breast from hyperlactation can lead to inflammation in the breast, which produces some of the early symptoms of mastitis, like breast soreness. Inflammatory mastitis can progress to bacterial mastitis, which is when a bacterial infection develops, usually requiring antibiotics.

What Does Mastitis Feel Like?

Mastitis is most common in the first six weeks of breastfeeding when you are most likely to experience engorgement. The good news is that your chances of developing mastitis decrease by 3 months postpartum.

Mastitis symptoms aren’t usually subtle—if you have mastitis, you will likely know it! Some of the most common symptoms of mastitis are:

• A tender area on one of your breasts

• A breast that is warm to the touch, and may have red streaks or a red rash

• Engorgement

• Feeling exhausted or sick

• Having the chills

• Experiencing a fever

Some parents wonder if it's safe to continue breastfeeding when they have signs of mastitis, and may be concerned about possibly passing along an infection to their baby. According to the National Library of Medicine, it’s perfectly safe to breastfeed if you have signs of mastitis—in fact, you should be encouraged to do so. It’s also safe to continue breastfeeding if you are taking antibiotic medication for bacterial mastitis.

How To Treat Mastitis

In the past, many parents were told that the best way to treat mastitis was to pump or nurse more frequently, as though to release the clogged up sensation in the breast. But new ABM guidelines recommend against this practice, and encourage parents to continue nursing on demand, but not more than usual.

Additionally, the follow measures are recommended to treat mastitis by the ABM:

• Use cold therapy for the breast, not heat

• Take over-the-counter painkillers, including anti-inflammatory pain medication, as per physician instruction

• Light massage of the affected area is fine, but don’t use deep pressure massage

• Consider a sunflower or soy lecithin supplement to decrease inflammation; 5-10 grams per day is recommended

• If you have developed flu-like symptoms or a temperature, talk to your doctor or midwife about antibiotic treatment for bacterial mastitis

How To Prevent Mastitis

If you have dealt with mastitis in the past or are concerned about developing it in the future, there are steps you can take to prevent it. This includes not pumping more than your baby needs, and not pumping after a feed. Ensuring that your baby has a good latch and is draining your breast well is helpful too. Wearing a supportive bra that isn’t too tight also helps prevent mastitis. When possible, avoid using nipple shields.

The Bottom Line

Mastitis can be a pain (quite literally!), but it’s temporary, and there are several simple ways to soothe your discomfort and treat the condition. If you develop signs of an infection, such as fever or flu-like symptoms, make sure to reach out to your doctor or midwife—infections are usually cleared up quickly with a course of antibiotics.

Most of all, you should know that you aren’t alone. Most breastfeeding parents deal with mastitis at one time or another, and it doesn’t have any long-term impacts on your ability to breastfeed your baby or make milk. Most importantly, with treatment, you will feel like yourself again before you know it.

About the Author

Wendy Wisner is a freelance writer and board certified lactation consultant (IBCLC) whose work has appeared on/in The Washington Post, Family Circle, ELLE, ABC News, Parents Magazine, Scary Mommy, Healthline, WebMD, Fit Pregnancy, Brain Child Magazine, Lilith Magazine, and elsewhere. Find her at www.wendywisner.com

Works Cited

Blackmon MM, Nguyen H, Mukherji P. Acute Mastitis. [Updated 2023 Jan 3]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023

Cleveland Clinic. Mastitis. Updated 2023.

Mitchell KB, Johnson HM, Rodríguez JM, et al. Academy of Breastfeeding Medicine Clinical Protocol #36: The Mastitis Spectrum, Revised 2022 [published correction appears in Breastfeed Med. 2022 Nov;17(11):977-978]. Breastfeed Med. 2022;17(5):360-376. doi:10.1089/bfm.2022.29207.kbm