What a blocked milk duct is
A blocked milk duct means that milk is not draining well from a specific area of the breast. You often feel a hard, tender spot or a lump, sometimes with mild redness. It often starts on one side and feels especially uncomfortable when breastfeeding or pumping.
Important: a blocked milk duct is not automatically an infection. Often it begins as a mechanical problem of drainage, swelling, and tissue pressure. This can develop into inflammation, and in some cases into bacterial mastitis. Clinical guidance therefore often refers to the mastitis spectrum. Academy of Breastfeeding Medicine: Protocol 36, Mastitis Spectrum
Common causes and triggers
A blocked milk duct rarely has a single cause. Often it’s a combination of more milk than drainage, external pressure, and a breastfeeding rhythm that isn’t fitting at the moment.
- Unusually long gaps between breastfeeding or pumping
- Sudden changes in daily routine, less sleep, stress, travel
- Pressure on the breast from a tight bra, strap, lying on the stomach, or an awkward sleeping position
- Sore nipples or latch problems, leading to ineffective emptying
- Too much or too vigorous pumping, which can increase tissue swelling
- Rapid reduction of feeds during weaning
How to recognize and assess a blocked milk duct
A blocked milk duct is usually localized. You have a distinct point of pain or a lump but otherwise don’t feel widely ill. A mildly elevated temperature can occur, but high fever and pronounced illness are more consistent with mastitis.
More likely a blocked duct
- Localized lump or firm spot
- Pain mainly with pressure, movement, or breastfeeding
- 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
- Chills, body aches, marked malaise
- Increasing redness and warmth that spreads
- Rapid worsening instead of gradual improvement
If you feel systemically unwell, have a low threshold for getting evaluated. Guidance on mastitis often emphasizes that breastfeeding is usually continued while the cause is treated. Information on mastitis (NHS)
Blocked milk duct: what to do — measures that really help
The goal is not to force everything out. The goal is to reduce swelling, improve drainage, and avoid overstimulation. Many escalations happen because people become too aggressive in a stressed state.
1) Continue emptying, but physiologically
Breastfeeding or pumping helps because it maintains drainage. At the same time, too-frequent or very strong pumping can irritate the breast. A good principle is: regular and gentle, not maximal and frantic.
- Continue breastfeeding on demand, without extra marathon sessions
- If you pump, use moderate suction and realistic intervals
- If breastfeeding is very painful, changing position can shift the pressure point
2) Cold or heat
This is a common question. Swelling is a major part of the problem in a blocked duct. Cooling between feedings can reduce swelling and ease pain. Heat can feel comforting briefly before feeding if it helps you relax, but prolonged heat can increase swelling.
- Cooling: between feedings, briefly and repeatable, if it helps you
- Heat: use briefly before breastfeeding if it eases emptying
- If heat increases pressure afterward, that’s a sign cooling is a better fit
3) Gentle massage instead of deep kneading
Many people press the lump hard. That can irritate the tissue. Often more helpful is a gentle, superficial motion that supports swelling toward lymphatic drainage, rather than pressing deeply on the tender point.
4) Reduce external pressure
An underrated step is to remove anything that adds pressure to the area. A too-tight bra, a hard underwire, bag straps, or persistent pressure while lying down can keep the blockage going.
5) Manage pain and inflammation realistically
If you have severe pain, it’s 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, medical history, and other medications. If in doubt, consult your healthcare provider or pharmacist.
Blocked duct during weaning or when you plan to breastfeed less
During weaning, a blocked duct often occurs because production reduces more slowly than removal. The most common mistake is either pushing through too hard or pumping too much. Both can prolong the problem.
A pragmatic approach is gradual reduction: empty enough to lower pressure, but not so much that your body interprets it as a signal to increase production. If you’re actively weaning and repeatedly get blockages, try smaller steps and avoid abrupt changes in intervals.
When to get evaluated
Many blocked ducts calm down noticeably within 24 hours. Evaluation is sensible if the course does not follow this pattern or if warning signs occur.
Seek evaluation if
- The area does not improve after 24 to 48 hours despite measures
- You develop a fever or feel clearly ill
- Redness spreads or the pain increases markedly
- You notice purulent discharge or the breast becomes extremely tender to pressure
- You get repeated blockages in a very short time
Antibiotics and mastitis
Antibiotics are not the standard solution for every blocked milk duct. They are considered mainly when bacterial mastitis is likely or when the clinical picture worsens significantly. If antibiotics are prescribed, the goal is to treat the infection while continuing milk removal as appropriate, not to stop breastfeeding abruptly.
Common mistakes that can prolong a blocked duct
- Too aggressive massage, strong pressing or kneading of the lump
- Prolonged heat that increases swelling
- Overpumping out of fear, which can drive production further
- Too-tight clothing or persistent pressure on the area
- Weaning in one big step instead of in small reductions
If you feel you’re going in circles, lactation support or a medical assessment is often faster than trying another new trick.
Conclusion
Blocked milk ducts are common, painful, and usually treatable if you reduce swelling, empty gently, and avoid overstimulation. Cooling between feedings, physiologic breastfeeding or pumping, and reducing external pressure are the most effective steps for many. If fever, marked illness, or rapid worsening occur, be evaluated for possible mastitis.
