Blocked Ducts While Breastfeeding: What We Now Know
A blocked duct is one of those breastfeeding problems that tends to arrive without warning — a tender, hard area in the breast, sometimes with a visible lump, that can feel alarming if you do not know what it is or what to do about it.
The good news is that most blocked ducts resolve within a day or two with the right approach. The less straightforward news is that thinking around blocked ducts has shifted significantly in recent years, and some of the advice that has been passed around for a long time — heat, vigorous massage, power pumping — is no longer recommended and may actually make things worse.
This post explains what we now understand about blocked ducts, what helps, and when to seek support.
What is a blocked duct — and has the thinking changed?
For a long time, a blocked duct was described exactly as it sounds: a plug or clog of thickened milk blocking one of the tiny tubes that carry milk from the breast to the nipple.
Current thinking has moved away from this explanation. Research now suggests that what we call a "blocked duct" is better understood as localised breast inflammation — swollen breast tissue that surrounds and narrows a duct, slowing milk flow in that area. Once milk flow slows in one spot, nearby ducts can be affected too, a bit like a traffic jam spreading back from one blocked junction.
This shift in understanding matters because it changes what we should and should not do about it.
What causes a blocked duct?
Anything that interferes with milk flowing freely and regularly from all areas of the breast can cause localised inflammation. Common causes include:
A shallow latch, where the baby is not drawing milk efficiently from the breast
Going too long between feeds or missing feeds without expressing
Pressure on the breast from a tight bra, a bag strap, or a sling pressing into breast tissue
Feeding in the same position every time, which may mean certain areas of the breast drain less well
A blocked nipple pore (sometimes called a bleb or milk blister), which can obstruct flow at the nipple itself
Oversupply, where more milk is being made than the baby removes
Previous breast surgery or scar tissue
What does a blocked duct feel like?
The most common signs are:
A localised area of tenderness or pain in the breast
A firm or lumpy area under the skin
Redness over the affected area in some cases
Milk from that area may look stringy or thickened
Importantly, a blocked duct on its own should not make you feel unwell. If you develop a temperature, flu-like aching, or feel genuinely ill, this is a sign that the inflammation may have progressed to mastitis and you should contact your GP or a healthcare professional promptly.
What helps — and what to avoid
Keep milk moving — gently
The single most important thing you can do is keep milk moving from the breast. Feed your baby frequently — at least every two to three hours — and make sure they are latching deeply, with a good mouthful of breast tissue, not just the nipple. A deep latch is far more effective at draining the breast than a shallow one.
If your baby is not feeding, hand express or use a pump to keep milk flowing. The aim is comfort, not emptying — avoid pumping aggressively or beyond what your baby needs, as this can stimulate more milk and worsen the engorgement.
Cold, not heat
This is one of the areas where advice has changed most clearly. Heat encourages blood flow to an area and can increase swelling and inflammation. Cold therapy — a cold compress or a bag of frozen peas wrapped in a cloth applied between feeds — can help reduce pain and inflammation. Many mothers find this more comfortable than heat, which may have been providing short-term relief while prolonging the problem.
Warm water in the shower for comfort is generally fine, but sustained application of heat pads or warm compresses to the affected area is no longer recommended.
Gentle movement — not vigorous massage
Vigorous massage of a blocked duct is another piece of advice that has fallen out of favour. Rough handling of inflamed breast tissue can increase damage and worsen inflammation. If you want to use massage, keep it very gentle — no more pressure than you would use applying a moisturiser. Light lymphatic drainage — soft, circular strokes moving from the breast towards the armpit — may help shift excess fluid. But firm or deep massage of the tender area is not recommended.
Rest and pain relief
Rest matters — though it is easier said than done with a new baby. Ibuprofen (if you are able to take it) can help reduce both pain and inflammation, and is compatible with breastfeeding. Paracetamol can help with pain. If you are unsure about any medication, ask your pharmacist or GP.
What about lecithin?
Lecithin is a supplement that has long been recommended for blocked ducts, with the theory that it reduces the thickness of breast milk. Since the idea of thickened milk as the cause of blocked ducts has fallen out of favour, lecithin is less commonly recommended now. Some practitioners still suggest it for mothers with recurring blocked ducts; others do not. If you are considering it, it is worth discussing with an IBCLC first.
What about unusual feeding positions?
You may have come across advice to feed your baby in unusual positions — dangling over them while on all fours, or pointing their chin towards the blocked area. The evidence does not support these as effective strategies, and some practitioners suggest they may worsen inflammation. Getting a good, deep latch in a comfortable, sustainable position is more useful.
When to get help
Contact your GP or a healthcare professional if:
You develop a temperature, flu-like symptoms, or feel unwell — this may indicate mastitis
The blocked duct has not improved within 24–48 hours
You notice a lump that is not changing or is getting larger — not all breast lumps during breastfeeding are blocked ducts, and a persistent lump should always be checked
Contact an IBCLC if:
Blocked ducts are recurring — this usually points to an underlying cause worth investigating, such as latch, positioning, oversupply, or tongue function
You are not sure whether your baby is latching or draining the breast effectively
You are in pain and not sure what to do next
Recurring blocked ducts
If you are getting blocked ducts repeatedly, the pattern itself is telling you something. Recurring breast inflammation usually has an underlying cause — and finding that cause is far more useful than managing each episode separately. Common contributors include a shallow or ineffective latch, tongue tie affecting how well your baby drains the breast, oversupply, a consistently restrictive bra or sling, or previous breast surgery. An IBCLC can help you look at the full picture and identify what might be driving the pattern.
How I can help
A blocked duct that keeps coming back, or one that is not clearing despite doing the right things, is worth getting proper support for. It does not have to become the pattern of your breastfeeding experience.
If you are struggling — whether with a one-off blocked duct that is not shifting, or with recurring breast inflammation that is making feeding miserable — I am here to help. A Breastfeeding Consultation gives us time to look at how your baby is feeding, identify any contributing factors, and put a plan in place that works for you both.
Book a free introductory call →
This post draws on current evidence including the Academy of Breastfeeding Medicine Clinical Protocol #36 (2022)
