Breastfeeding Support

Why It is NOT a Plugged Duct

Have you ever noticed a sore, swollen spot on your breast while breastfeeding? Chances are that you were told it was a “plugged duct.” And for years, that’s exactly what lactation professionals were taught and what parents were told to treat.

As it turns out, what we considered a “plugged duct” is more complicated than we thought.

Recent research has helped us better understand what’s actually happening when these painful breast symptoms occur. I’m here to help you understand what’s going on so you can recover faster and avoid making inflammation worse.

Breastfeeding Should NOT Hurt

The discomfort or fullness you feel waking up to full breasts or after long stretches between nursing that goes away after breastfeeding is completely normal.

What we’re talking about is a new spot or area of the breast, or even the whole breast, that is…

• Tender or painful
• Swollen or firm
• Warm/hot to the touch
• Not improving after nursing or pumping

Pain is our body’s way of telling us that something is wrong. Healthy, lactating breasts should be relatively pain free! Any new swelling or tenderness that doesn’t go away with the next nursing session deserves attention and investigation.

What We Used to Believe About “Plugged Ducts”

We were all told that milk fat that sat still for too long would stick together in the ducts, forming a “glob” that could block milk flow. We were taught that this “glob” of milk fat or a “plug” was the tender lump you felt or caused an area to become hard/swollen. Parents would then notice the reduced milk output, and, for some parents, once the problem resolved, a thick strand of milk comes out.

As a result, to help with this problem, parents would be taught to…

• Nurse more on the affected side
• Apply heat to soften the “plug”
• Massage the area deeply or firmly to push the “plug” out

Turns out, these recommendations were counterproductive to what parents should be doing.

What Research Has Taught Us

Thanks to the unique perspective of breast surgeon and IBCLC, Dr. Katrina B Mitchell, her understanding of the structures and physiology of breasts from a surgeon’s viewpoint has improved how we approach painful breast symptoms.

Dr. Mitchell, whom I had the great pleasure of hearing speak at the International Lactation Consultants Association Conference in 2021, explained that milk ducts are microscopic. Even if milk fat could stick together in the duct, it would be far too small to create a lump that we could feel or see.

So now you may be asking, what is it then?

Dr Mitchell says, “It’s not a plugged duct. It’s a duct being compressed by swelling and what you are feeling is just the inflammation.”

If milk sets in the breast for “too long” as a result of prolonged time between milk removal/expression (i.e., not feeding as frequently), that extra milk volume starts to push against other tissues.

Too much of this pressure in one area tells our body it is getting damaged, triggering our immune system. Much like your body responds to any other injury, it sends extra fluid, blood and immune cells to that area to start the healing process. The problem with this is that all that extra fluid leads to more of the swelling, resulting in an additional inflammatory response.

As a result, we encounter a frustrating cycle: inflammation causes swelling, swelling pushes in on the milk ducts and narrows them, narrowed ducts make milk removal difficult, sitting milk creates more pressure, pressure triggers inflammation, and around again it goes.

So instead of milk fat blocking the milk flow within the duct itself, it’s the inflammation around it squeezing the milk duct shut. The thick, stringy milk that some parents see come out wasn’t the cause of the swelling, rather the milk thickened because there wasn’t space for all of it to move through the duct freely until the inflammation was resolved.

Where Does Mastitis Come into Play?

To start, let’s break down the term “mastitis”…

Mast- = breast
-itis = inflammation

So “mastitis” simply means inflammation of the breast, but isn’t that what we’ve been talking about? Yes. However, there is a spectrum of mastitis that starts with simple inflammatory mastitis and can lead to bacterial infection, but not all mastitis is a bacterial infection.

In the early stages of swelling/tender spots, it does not automatically mean a bacterial infection. Even in cases where the swollen area is hot to the touch with a low-grade fever and flu-like symptoms, it isn’t necessarily bacterial mastitis yet.

According to the Academy of Breastfeeding Medicine (ABM) Clinical Protocol #36: The Mastitis Spectrum, if symptoms have not improved after 24 hours of appropriate care (see protocol that follows), it’s time to contact your healthcare provider for evaluation.

Please Note: The protocol found below is an outline of information from ABM’s Protocol #36 to help you avoid doing something that could increase inflammation. This is NOT meant to be a method of diagnosis, nor should the tips below be used without also seeking help from an IBCLC or your doctor. You will want to investigate the cause of the swelling in the first place to avoid recurrence.

What You Should Do Instead: The New Technique

Since the problem is inflammation, not a plug, the goal is to reduce the inflammation/swelling.

Current recommendations include…

Ice, Ice, Ice

Cold is one of the best tools for reducing inflammation.

While using a cloth as a barrier for your skin to avoid frostbite, apply ice or a cold pack for 10-20 minutes. Allow at least 30 minutes between sessions for your skin to recover.

Continue Your Normal Feeding Routine

Keep nursing or pumping per your regular routine.

Unless recommended by your healthcare provider or IBCLC, avoid extra nursing or pumping sessions on the affected side. Extra milk removal can increase milk production, which may contribute to increased milk volume stuck behind the squeezed/shut duct, and therefore increase pressure.

Prioritize Rest

Your body needs proper rest to heal.

We recognize that may be easier said than done when having to care for a newborn, but even small opportunities can support your recovery.

Talk to your Doctor about Anti-Inflammatories

NSAIDs, like ibuprofen, can also help reduce inflammation.

Consult with your healthcare provider first to ensure you are approved to take this kind of medication to help with any inflammation.

Avoid Deep Massaging

Contrary to preexisting advice, do not use deep massage on the affected area.

Since there isn’t actually a “plug” that we’re trying to push out, deep massage can simply lead to bruising and increased inflammation.

Try Lymphatic Drainage

Lymphatic drainage involves very light pressure, sweeping/brushing motion.

With your hands, sweep from the base of your breast, over the swollen area, all the way up to your armpits and collarbone. Repeat this light sweeping/brushing motion upward for 1-2 minutes at a time. The goal is to gently move the extra fluid out of the breast tissue and into the lymph glands in your armpits and around your collarbone. Pressure should be no greater than putting on lotion. This can be done as many times a day as needed. (Detailed steps can be found in the PDF of ABM’s Protocol #36.)

Don’t Ignore Persistent Symptoms

Remember, if pain, swelling, and fever or flu-like symptoms have not improved after 24 hours despite trying the recommendations above, contact your healthcare provider or an IBCLC. You can find IBCLC providers in your area on the International Lactation Consultant Association’s website: https://ilca.org/

I hope this new information is helpful for your parenting journey and has provided you more guidance on what to do/not do when you notice new painful areas in the breast. Remember, when inflammation is the problem, the first step is to reduce the swelling.