Reasons for blocked ducts

Blocked or plugged ducts is a condition where a blockage in a milk duct results in poor or insufficient drainage of the duct. When milk builds up behind the blockage, the concentration of pressure in the duct may lead to local discomfort in the breast, or a lump may form.
Breastfeeding mother wih blocked ducts

It is not always clear why blocked ducts occur; however, insufficient breast drainage is most likely the cause. Poor drainage may be caused by the baby not attaching well to the breast, tight clothing around the breast, long periods between breastfeeds or scarring from surgery. Blocked ducts can also lead to mastitis if not cleared. 

Signs of a blocked milk duct

The signs of a plugged duct may be gradual. A blocked breast duct may appear as a tender lump the size of a pea or larger, and occasionally presents with a small white blister on the nipple. The breast may be sensitive and the tender lump may or may not be palpable with defined margins, the area should emit little or no heat, and occur without either redness or fever (< 38.4 °C). The baby may be fussy when feeding from the affected breast, since the milk flow rate from the breast may be reduced. The mum's general state of health is not affected by blocked ducts.

Evaluation of blocked milk ducts

Consultation with a lactation consultant or healthcare professional is a necessary first step. If the breast is red, it may also be engorged. If fever is present or the mum is unwell, mastitis may be present. 

Management

A management plan should be implemented and monitored with a lactation consultant or healthcare professional. The key to managing blocked ducts is promoting removal of milk from the blocked area.

In conjunction with advice from a healthcare professional, evidence-based strategies that may be implemented include:

  • Help with positioning and attachment, trying different feeding positions to try and clear the blockage
  • Feeding with the affected side first and frequent breastfeeding to help clear the blockage, with no more than three hours between breastfeeds and 8-12 feeds a day
  • Massaging the affected area before and during breastfeeding; breast massage under a warm shower
  • Temporarily expressing after the breastfeed, using the hands or a pump
  • Avoiding tight clothing, such as underwired bras
  • Resting as much as possible
  • Warming the breast with heat packs before feeding to help stimulate milk flow and cooling with cool packs after a feed to help relieve pain and inflammation

If the blockage is not cleared after 24-48 hours, or if flu-like symptoms develop or deterioration is present, the mum should consult a doctor, as blocked ducts can lead to mastitis.

Study abstracts
S3-Guidelines for the Treatment of Inflammatory Breast Disease during the Lactation Period: AWMF Guidelines, Registry No. 015/071 (short version)

Breastfeeding is widely acknowledged to be the best and most complete form of nutrition for healthy infants born at term and is associated with numerous ...

Jacobs A, Abou-Dakn M, Becker K, Both D, Gatermann S, Gresens R, Groß M, Jochum F, Kühnert M, Rouw E, Scheele M, Strauss A, Strempel AK, Vetter K, Wöckel A (2012)

Geburtshilfe Frauenheilkd. 73(12):1202-1208
References

American Academy of Pediatrics and The American College of Obstetricians and Gynecologists. Breastfeeding handbook for physicians 2006).

Lawrence, R.A. & Lawrence, R.M. Breastfeeding: a guide for the medical profession (Elsevier Mosby, Maryland Heights, MO, 2011).

Amir, L.H. ABM Clinical Protocol #4: Mastitis, Revised March 2014. Breastfeed Med 9, 239-243 (2014).

Jacobs, A. et al. S3-Guidelines for the Treatment of Inflammatory Breast Disease during the Lactation Period: AWMF Guidelines, Registry No. 015/071 (short version) AWMF Leitlinien-Register Nr. 015/071 (Kurzfassung). Geburtshilfe Frauenheilkd. 73, 1202-1208 (2013).