Clogged duct or mastitis?

What changed about mastitis — and why most advice online is out of date

In 2022 the clinical guidance on mastitis was rewritten, and a lot of what mothers had been told for decades turned out to be making things worse. If you have been told to massage the lump hard, apply heat, and pump the breast empty, you have been given the old version. Here is the current one, and the reasoning behind it.

The old explanation, and why it was wrong

For years the story went like this: milk thickens, forms a plug inside a duct, and the duct blocks like a pipe. The fix followed logically — force the plug out. Massage hard, apply heat to loosen it, pump until the breast is empty.

The Academy of Breastfeeding Medicine's revised protocol describes something different. The ducts are not blocked by a solid plug. They are narrowed by inflammation in the surrounding tissue, which squeezes them from the outside and restricts flow. Nothing is stuck. The passage is swollen shut.

Once you see it that way, the old advice reads badly. Deep massage on inflamed tissue adds more swelling. Heat increases blood flow to an area that is already engorged. And pumping to empty the breast tells your body to make more milk, when too much milk is usually what started the problem.

It is a spectrum, not one condition

The protocol describes a continuum rather than a single illness, and knowing which part you are on changes what you should do.

• Engorgement — both breasts, painful and swollen, classically around days three to five after birth as your milk comes in.
• Ductal narrowing (what used to be called a plugged duct) — a firm, tender area in one breast, no fever, you otherwise feel well.
• Inflammatory mastitis — that area becomes swollen, warm and discoloured, and you may develop a fever and feel unwell. There is still no infection at this point.
• Bacterial mastitis — inflammation that has become an infection, and this is where antibiotics belong.
• Abscess — a collection of infected fluid, usually needing drainage rather than tablets alone.

Most people never get past the first two stages. The point of acting early is to stop the slide.

What to do

• Ice, not heat. The protocol calls cold the treatment of choice for the swelling. A cold pack or a cool cloth for around ten minutes, repeated, between feeds.
• Keep feeding your baby normally, on cue. Normal feeding is described as the best anti-inflammatory measure available — not extra feeds, not scheduled draining, just your usual pattern.
• Very light stroking only. If you touch the area at all, the guidance describes a touch "like you would use petting a cat", stroking gently towards your collarbone and armpit to help fluid drain away. Nothing deeper than that.
• A supportive bra that is comfortable and not tight. No underwires for now.
• Pain relief. Ibuprofen and paracetamol are usually appropriate — worth confirming with your pharmacist or doctor, particularly ibuprofen if you have other conditions.
• Rest. It sounds like a throwaway line, and it isn't. Rest and lower stress are listed alongside ice as part of the treatment.

What to avoid

• Deep massage. This is the biggest change. Digging into the lump, however determined you feel, increases the inflammation that is causing the narrowing.
• Electric toothbrushes and vibrating devices on the breast. These spread widely online and are specifically discouraged.
• Heat — hot showers aimed at the area, hot compresses, warm soaks.
• Soaking the nipple in saline, Epsom salts or castor oil. These can damage the skin.
• Cabbage leaves. No evidence behind them, and they can carry bacteria.
• Pumping to empty, or pumping extra. Removing more milk than your baby needs signals your body to produce more, which feeds the cycle.
• Popping a nipple bleb. That small white blister on the nipple should not be opened or picked. Ice it and get it looked at if it persists.

The stash problem

This one is worth saying plainly because so many mothers are encouraged into it. Pumping on top of full feeds to build a freezer stash raises your supply above what your baby actually removes. The guidance flags this directly, including low-suction silicone collectors, which also encourage overproduction.

Making more milk than your baby takes is one of the most common things sitting underneath repeated bouts of mastitis. If you keep getting it, oversupply is the first thing worth looking at — ideally with a lactation consultant, because bringing supply down safely is not something to improvise.

When to stop managing it at home

Contact your doctor or an out-of-hours service if:

• Symptoms are getting worse, or have not started improving within about 24 hours
• You have a temperature of 38.4°C (101°F) or above, chills, or flu-like aching
• The area becomes soft and squishy in the middle, or starts leaking pus — both can indicate an abscess
• You feel very unwell, regardless of what your breast looks like

Antibiotics are for bacterial infection, not for every red breast. A clinician makes that call. Taking them unnecessarily does not speed up inflammatory mastitis and carries its own costs.

Two questions almost everyone asks

Can I keep feeding from that breast? Yes, and you should. The milk is safe for your baby, including while you are on antibiotics for this in most cases. Stopping suddenly is the thing most likely to make it worse.

Do I need to throw milk away? No.

One honest caveat

The 2022 protocol is not universally accepted. A published commentary has argued it may lead to overtreatment in some situations, and clinicians continue to discuss it. What is not in dispute is the direction of travel on the practical advice: gentler, cooler, less forceful, and less pumping than mothers were told for years.

Sources: ABM Clinical Protocol #36: The Mastitis Spectrum, Revised 2022 · Minnesota Department of Health / WIC — Mastitis: Updated Guidance · La Leche League — Mastitis Spectrum Protocol tips · Douglas, commentary on Protocol #36 (2023)