Engorgement, blocked ducts, and mastitis

Around day three or four, the milk comes in. For some people this is a gradual fullness. For others it is an overnight transformation — breasts that were manageable yesterday are now rock hard, hot, and making the prospect of latching a baby onto them seem impossible. This is engorgement, it is temporary, and there are things that help.

Further along the line, you may encounter a blocked duct — a firm, tender lump that was not there yesterday. And if that blocked duct becomes infected, you will know: mastitis announces itself with flu-like symptoms, a fever, and a breast that has become visibly red and painful. Each of these is a different situation with a different response.

Engorgement

What is happening

Engorgement in the first few days happens as transitional milk replaces colostrum and the body, not yet calibrated to the baby's actual needs, often produces more than required. The breast tissue fills with milk, blood, and lymph fluid simultaneously. The result is firmness, warmth, and sometimes enough swelling that the nipple is flattened and difficult for the baby to latch onto.

Engorgement can also happen at any point when there is a longer-than-usual gap between feeds — a longer sleep, a missed feed, a sudden change in feeding frequency.

What helps

• Feed frequently. The most effective treatment is the one that empties the breast — a well-latched baby. Aim for 8–12 feeds in 24 hours.
• Warmth before a feed. A warm compress, or a warm shower, encourages the let-down reflex and makes the milk flow more easily.
• Cold after a feed. Cold compresses (a bag of frozen peas wrapped in a cloth, for example) reduce inflammation and discomfort between feeds.
• Gentle massage or hand expression before latching. If the areola is so firm the baby cannot latch, hand-express or use a warm compress to soften it enough to allow attachment.
• Avoid aggressive pumping. Pumping large volumes to relieve engorgement signals the body to produce more, which prolongs the cycle. Express only enough to soften the breast for latching.

Cabbage leaves: do they work?

Chilled cabbage leaves placed inside the bra are a traditional remedy with some trial evidence suggesting modest benefit for engorgement discomfort, possibly due to anti-inflammatory compounds and the cooling effect.¹ They are not harmful, they smell peculiar, and if they make you more comfortable, they are a reasonable option. They should not replace frequent feeding.

Blocked ducts

What is happening

A blocked (or plugged) duct is a localised area where milk flow is obstructed. This may happen because of pressure on the breast (a too-tight bra, sleeping in one position, a bag strap), incomplete drainage, or no obvious reason at all.

You will typically notice a firm, tender lump — sometimes with a red area on the overlying skin. It may feel like a pea or a grape. It is generally not accompanied by fever, and you do not feel systemically unwell.

What helps

• Keep feeding from the affected breast. This is the most important thing. Stopping or reducing feeds delays resolution and risks progression to mastitis.
• Position the baby with their chin pointing toward the lump. The jaw action during feeding is most effective at draining the area the chin is closest to.
• Warm the area before feeds.
• Gentle massage toward the nipple during feeding can help move the blockage.
• Vary feeding positions to ensure different areas of the breast are drained.

Most blocked ducts resolve within one to two days of active management. If a lump persists beyond a few days or you develop a fever, the situation has changed.

Mastitis

What is happening

Mastitis is inflammation of the breast tissue — with or without infection. It usually develops when a blocked duct is not resolved and milk stasis allows bacteria to multiply, or when bacteria enter through a cracked nipple.

Symptoms that distinguish mastitis from a blocked duct:

Mastitis can feel sudden and severe. Many people describe feeling worse than they have felt since early labour. It is not minor.

What helps

• Do not stop feeding from the affected breast. The AAP and NHS both advise continuing to breastfeed during mastitis.²³ Stopping allows milk to stasis further and worsens the infection risk. Breast milk from an affected breast is safe for the baby.
• Feed frequently, starting on the affected side.
• Rest. Mastitis responds poorly to being pushed through.
• Ibuprofen is the preferred analgesic — it reduces both pain and inflammation. Paracetamol can be taken alongside it. Both are compatible with breastfeeding.
• Antibiotics. If symptoms do not improve within 12–24 hours of self-care measures, contact your GP for antibiotics. Mastitis caused by bacterial infection requires antibiotic treatment — it will not resolve on its own.²

Completing the antibiotic course

If antibiotics are prescribed, complete the full course even if you feel better after 48 hours. Stopping early is a common cause of recurrent mastitis.

Breast abscess

An abscess is a collection of pus within the breast. It develops when mastitis is not treated promptly or adequately. Signs include a fluctuant (soft, fluid-filled) lump within a previously inflamed area, fever that is not resolving despite antibiotics, and worsening rather than improving pain.

An abscess requires same-day medical assessment. Treatment is usually drainage — either by needle aspiration or, in some cases, a small surgical procedure. You can usually continue breastfeeding from the affected breast throughout, though feeding directly over the abscess site may not be possible during the procedure.

Recurrent mastitis

One or two episodes of mastitis are common. Recurrent episodes — three or more — warrant further investigation. Possible causes include an underlying structural abnormality, incomplete antibiotic courses, persistent poor latch or drainage, or — rarely — an underlying condition. An IBCLC assessment of latch and drainage alongside GP review is appropriate.

When to call your pediatrician or GP

Same day (contact your GP):

• Fever above 38.5°C (101.3°F) with breast redness and flu-like symptoms — mastitis
• Mastitis symptoms not improving after 24 hours of self-care
• A painful fluctuant lump developing within an inflamed area — possible abscess
• Cracked nipples that are not healing or show signs of infection (spreading redness, pus)

Routine appointment:

• Recurrent blocked ducts (more than two or three in the first few months)
• Recurrent mastitis — needs investigation

Go to A&E or call 999:

• High fever above 39°C (102.2°F) with rapid deterioration, confusion, or feeling seriously unwell — rare but possible sign of severe infection requiring urgent treatment

Tracking in PooPeeMilk

Logging feeds and which breast you used helps you ensure both breasts are being drained regularly — the simplest preventive step for blocked ducts and mastitis. If you are managing a blocked duct, noting which side and when it started gives you a timeline to share with your midwife or GP if it does not resolve.

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Also in this cluster: Oversupply and fast letdown · Pumping basics · Latch and positioning

Sources

• Snowden HM, Renfrew MJ, Woolridge MW. "Treatments for breast engorgement during lactation." Cochrane Database of Systematic Reviews 2001, Issue 2. Cochrane Library.
• NHS. "Mastitis." NHS.uk. https://www.nhs.uk/conditions/mastitis/
• AAP. "Breastfeeding and the Use of Human Milk." Pediatrics 150(1), 2022. https://publications.aap.org/pediatrics/article/150/1/e2022057988/188347/Breastfeeding-and-the-Use-of-Human-Milk