Blocked Ducts

What a blocked duct actually is

The Academy of Breastfeeding Medicine's 2022 protocol calls "plugging" a colloquial term for microscopic ductal inflammation and narrowing, related to alveolar distension and disruption of the breast's own microbiome. It then makes a statement that contradicts almost everything written on this subject before 2022: ducts in the breast "are innumerable and interlacing and it is not physiologically or anatomically possible for a single duct to become obstructed with a macroscopic milk 'plug'".

So the lump you can feel is not a bead of thickened milk sitting in a tube. It is a segment of breast where the ducts are narrowed by swelling and the surrounding tissue is congested. That changes what helps.

The NHS describes it more traditionally — a small, tender lump caused by engorgement, a missed feed, or pressure from a tight bra, bag strap or clothing. Those triggers are still right; the mechanism underneath is now understood differently.

What it feels like

The ABM protocol describes ductal narrowing as a focal area of firmness, or more generally congested breast tissue, that is tender. It may look mildly red from lymphatic congestion, and — importantly — there are no systemic symptoms. No fever, no chills, no flu-like feeling. Once those appear, you are dealing with inflammatory or bacterial mastitis, not a blocked duct.

The protocol also reassures on something that sends a lot of people into a panic: many people feel normal lactating glandular tissue and interpret it as plugging. Lactating breasts can feel lumpy and even painful at times, and that is uncomfortable rather than abnormal. Pain and redness in the morning after a long stretch of sleep represent alveolar distension and swelling, not infection — infection does not develop over a few hours.

What helps

• Feed responsively on both sides. The protocol notes patients may feel relief from a "plug" with breastfeeding because it decreases alveolar distension.
• Ibuprofen and paracetamol. Ibuprofen tackles the inflammation that is the actual problem. The ABM protocol gives ibuprofen 800mg every 8 hours and paracetamol 1,000mg every 8 hours in the acute phase, where these are appropriate for you.
• Cold. Ice can be applied every hour or more frequently. Cold reduces the oedema that is narrowing the ducts.
• Light lymphatic drainage. The protocol says the most successful technique "approximates manual lymphatic drainage with light sweeping of the skin rather than deep tissue massage". Sweep gently towards the armpit.
• A well-fitting supportive bra without wires, and no straps or waistbands pressing into the breast.
• Rest, and treat the cause. If the trigger was a missed feed, a long night, a tight bra or a pump session that was too long, fix that.

Sunflower or soy lecithin 5-10g daily is mentioned in the protocol as a way to reduce ductal inflammation and emulsify milk. Evidence is limited; it is low-risk and widely used.

What makes it worse

These are the interventions the 2022 protocol specifically warns against, and they are all things that used to be routinely recommended:

• Squeezing or aggressive massage. "Attempts to extrude a 'plug' or milk precipitate by squeezing or aggressively massaging the breast are ineffective and result in tissue trauma." Deep massage causes increased inflammation, tissue oedema and microvascular injury, and can propagate a phlegmon — an ill-defined inflammatory mass that may then need extended antibiotics.
• Vibrating devices. Electric toothbrushes and commercial massagers are named and advised against.
• Repeatedly feeding or pumping the affected side to "clear" it. The protocol is blunt: "repeated feeding in an attempt to relieve the 'plug' will suppress [feedback inhibition of lactation], increase milk production, and ultimately exacerbate inflammation and ductal narrowing."
• Dangle feeding. No evidence supports feeding an infant on the floor with the mother hovering above, and the protocol raises safety concerns about unsafe positions. Safe variations on standard positions may improve comfort but do not address the inflammation.
• Heat, castor oil, saline soaks and Epsom salt soaks. All advised against; the protocol notes silicone pumps filled with Epsom salt can macerate skin.
• Unroofing a nipple bleb with a needle. The protocol says do not, because it causes trauma and further narrowing. Oral lecithin and a moderate-potency topical steroid such as 0.1% triamcinolone can be used instead, wiped off before feeding.

When to call

Contact your GP, NHS 111, out-of-hours service or public health nurse if:

• You develop a fever, chills or flu-like symptoms — that is mastitis, not a blocked duct, and it needs assessment. The NHS advises contacting your GP or NHS 111 if you are no better within 12 to 24 hours or feel worse at any time.
• A red or darker area is spreading, or you can see streaks.
• A lump does not shrink as milk is removed, or does not respond to the measures above. La Leche League GB names this as a possible abscess, which needs urgent treatment.
• You are getting repeated episodes. The ABM protocol lists recurrent hyperlactation, dysbiosis and failure to address the underlying cause as the usual reasons, and treating those is more effective than treating each episode.

Call your local emergency number (999 in the UK and Ireland, 911 in the US and Canada, 000 in Australia, 111 in New Zealand) if you become confused, severely breathless, or collapse.

Where to get real help

Most breastfeeding problems are solved faster by someone watching a feed than by reading about them. In the UK the National Breastfeeding Helpline is 0300 100 0212 and, as its operators the Breastfeeding Network and the Association of Breastfeeding Mothers state, it is open "24 hours a day, 365 days a year", with support also available in Welsh, Polish, Bengali and Sylheti (nationalbreastfeedinghelpline.org.uk). La Leche League GB runs local groups and a helpline; in Ireland the HSE offers an "Ask our breastfeeding expert" live chat and email service. An IBCLC is an International Board Certified Lactation Consultant, the only internationally accredited lactation qualification — you can check credentials through IBLCE. Your midwife, health visitor or public health nurse can also refer you.