What a blocked milk duct is
A blocked milk duct means that milk drains less well from a specific area of the breast. You often feel a hard, tender spot or a lump, sometimes with slight redness. It often starts on one side and can feel particularly uncomfortable during breastfeeding or pumping.
Important: a blocked duct is not automatically an infection. Often it is initially a mechanical problem of drainage, swelling and pressure in the tissue. This can develop into inflammation, and in some cases into bacterial mastitis. Clinical guidance therefore often refers to a mastitis spectrum. Academy of Breastfeeding Medicine: Protocol 36, Mastitis Spectrum
Typical causes and triggers
A blocked duct rarely has a single cause. It is often a combination of more milk than drainage, external pressure and a feeding rhythm that does not fit at the time.
- Unusually long gaps between feeds or pumping
- Sudden changes in daily routine, less sleep, stress, travel
- Pressure on the breast from a tight bra, shoulder strap, lying on the tummy or an unfavourable sleeping position
- Sore nipples or attachment problems, leading to ineffective emptying
- Too much or too vigorous pumping, which can increase swelling in the tissue
- Rapid reduction of feeds during weaning
How to recognise and assess a blocked duct
A blocked duct is usually localised. You have a clear point of pain or a lump, but do not otherwise feel severely ill. A slightly raised temperature can occur, but high fever and marked malaise are more typical of mastitis.
More likely a blocked duct
- Local lump or firm area
- Pain mainly with pressure, movement or feeding
- No pronounced feeling of being unwell
- It improves noticeably within 12 to 24 hours with appropriate measures
More likely signs of mastitis
- Fever that persists or rises
- Shivering, body aches, marked feeling of being unwell
- Redness and warmth that increase and spread
- Rapid worsening instead of gradual improvement
If you feel systemically unwell, the threshold for assessment should be low. Guidance on mastitis symptoms often emphasises that breastfeeding should usually continue while the cause is treated. NHS: Mastitis
Blocked duct — what to do: measures that really help
The goal is not to force everything out. The aim is to reduce swelling, improve drainage and avoid overstimulation. Many escalations happen because people become too aggressive when stressed.
1) Continue to empty, but gently
Breastfeeding or pumping helps because it maintains drainage. At the same time, very frequent or very forceful pumping can further irritate the breast. A good principle is: regular and gentle, not maximal and frantic.
- Continue to breastfeed as needed, without extra marathon sessions
- If you pump, use moderate suction and realistic intervals
- If feeding is very painful, changing position can alter the pressure point
2) Cooling or warming
Many people ask about this. Swelling is a large part of the problem in a blocked duct. Cooling between feeds can reduce swelling and ease pain. Warmth can feel pleasant just before feeding if it helps you relax, but prolonged heat can increase swelling.
- Cooling: between feeds, short and repeatable, if it helps you
- Warmth: rather short before feeding, if it facilitates emptying
- If warmth increases pressure, that is a sign cooling is better
3) Gentle massage instead of deep kneading
Many people squeeze the lump strongly. That can irritate the tissue. Often more helpful is a gentle, superficial movement that supports swelling reduction towards the lymphatic drainage, rather than pressing deeply on the painful spot.
4) Reduce external pressure
An underestimated step is to remove anything that adds compression to the area. A bra that is too tight, a hard underwire, shoulder straps or continual pressure while lying down can keep the blockage going.
5) Manage pain and inflammation realistically
If you have severe pain, it is not a test of character. Anti-inflammatory measures can help, because less swelling often means less blockage. What suits you depends on your situation, including breastfeeding, pre-existing conditions and other medications. If unsure, seek advice from your GP or pharmacist.
Blocked duct during weaning or when you want to feed less
During weaning a blocked duct often arises because production falls more slowly than removal. The most common mistake is either persisting too rigidly or pumping too vigorously. Both can prolong the problem.
A pragmatic approach is gradual reduction: empty enough to reduce pressure, but not so much that the body interprets it as a signal to increase production. If you are actively weaning and repeatedly get blockages, it is worth making smaller steps and avoiding abrupt changes in intervals.
When you should get it checked
Many blocked ducts improve noticeably within 24 hours. Assessment becomes sensible if the course does not follow this pattern or if warning signs appear.
Get checked if
- The area does not improve after 24 to 48 hours despite measures
- You develop a fever or feel clearly unwell
- The redness spreads or the pain increases markedly
- You notice pus-like discharge or the breast becomes extremely tender to pressure
- You have repeated blocked ducts in a very short time
Antibiotics and mastitis
Antibiotics are not the standard solution for every blocked duct. They are mainly considered when bacterial mastitis is likely or when the clinical picture clearly worsens. When antibiotics are prescribed, the aim is to treat the infection while allowing milk flow to continue, not to stop breastfeeding abruptly.
Common mistakes that can prolong a blocked duct
- Too aggressive massage, strong pressing or kneading of the lump
- Prolonged warmth that increases swelling
- Over-pumping out of fear, which further stimulates production
- Too-tight clothing or sustained pressure on the area
- Weaning in a large step instead of in small reduction steps
If you notice you are stuck in a loop, breastfeeding support or a medical assessment is often quicker than trying another new trick.
Conclusion
A blocked milk duct is common, painful and usually manageable if you reduce swelling, empty gently and avoid overstimulation. Cooling between feeds, physiological breastfeeding or pumping and less external pressure are the most effective steps for many. If fever, marked malaise or rapid deterioration appear, it should be checked to rule out mastitis.
