Mastitis vs. a Clogged Duct: What to Know

Breastfeeding breast pain is often described as a “clogged duct,” but current lactation guidance views many of these symptoms as part of an inflammatory spectrum rather than a literal chunk of milk that simply needs to be squeezed out.

I'm Dr. Monica, a board-certified OBGYN and mom of three. The most important thing is recognizing when inflammation can be managed conservatively and when symptoms need medical evaluation.

What can a “clogged duct” feel like?

You may notice a tender, firm or swollen area of the breast without feeling systemically ill. Local inflammation can make milk flow less comfortably and may feel worse after a long interval between feeds or pumping sessions.

The Academy of Breastfeeding Medicine's mastitis-spectrum protocol advises against repeated deep massage or forceful attempts to “work out” a plug because additional tissue trauma can worsen swelling and inflammation.

What helps with inflammatory symptoms?

Current mastitis-spectrum guidance emphasizes normal physiologic milk removal rather than repeatedly trying to empty the breast beyond the baby's needs. Comfort measures can include cold packs and anti-inflammatory pain medication when medically appropriate for you. Avoid aggressive breast massage.

If pumping, use settings and flange sizes that are comfortable rather than turning suction up in an attempt to force milk through.

When does mastitis become more concerning?

Mastitis can involve breast redness, warmth, swelling and significant tenderness along with fever, chills, body aches or a flu-like feeling. ACOG notes that bacterial mastitis may require antibiotics, and breastfeeding can generally continue during treatment.

Call your clinician if you have fever or systemic illness, rapidly worsening redness or pain, symptoms that are not improving, or concern for an abscess.

When to seek prompt evaluation

Seek medical care promptly for severe or rapidly worsening symptoms, persistent high fever, spreading redness, significant dehydration, or a breast mass that is becoming more fluctuant or intensely painful. An abscess may require imaging and drainage rather than simply another round of home measures.

One thing I would stop doing

If advice tells you to knead the painful area as hard as possible, have someone “massage the clog out,” or repeatedly pump to completely empty the breast, that can be counterproductive. More stimulation can increase milk production, while aggressive pressure can increase tissue swelling.

Medical sources

• Academy of Breastfeeding Medicine, Clinical Protocol #36: The Mastitis Spectrum, Revised 2022: https://pubmed.ncbi.nlm.nih.gov/35576513/
• ACOG, Benign Breast Problems and Conditions: https://www.acog.org/womens-health/faqs/benign-breast-problems-and-conditions
• ACOG, Breastfeeding Challenges: https://www.acog.org/clinical/clinical-guidance/committee-opinion/articles/2021/02/breastfeeding-challenges

Educational information only. Breast pain with fever, systemic illness, worsening redness, or concern for abscess needs individualized medical evaluation.