Causes of Clogged Milk Ducts

Most Commonly Caused by Breastfeeding, but Sometimes Not

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Clogged milk ducts are a common problem that many breastfeeding people experience. Changes in feeding schedules, poor drainage of the milk duct, as well as tight clothing, often cause the condition.

In most cases, the blockage can be managed at home by massaging the breast and pumping or nursing more frequently. But if the lump doesn't go away with proper treatment, it may signify a more serious condition, such as mastitis or, in rare cases, breast cancer.

This article discusses the causes of a clogged milk duct, how it's treated, and when to see a healthcare provider.

A mother working and breastfeeding her child

Anchiy / Getty Images

Signs of a Clogged Milk Duct From Breastfeeding

A clogged milk duct feels like a sore, tender lump in the breast. The pressure that builds up behind the clogged duct causes inflammation and irritation. This can happen for several reasons, including breastfeeding only on one breast, severe engorgement (when the breast overfills with milk), skipping feedings, or wearing a bra that is too tight.

Signs and symptoms often occur in one breast at a time. They may include:

  • Breast tenderness
  • A lump the size of a pea or larger in one area of the breast
  • Heat and redness around the lump
  • A small white spot on the nipple tip
  • Decreased milk supply in one breast

Causes of Non-Pregnancy Blocked Ducts

Although more common among breastfeeding individuals, blocked milk ducts may also be caused by conditions other than pregnancy and nursing.

Mammary Duct Ectasia

Mammary duct ectasia is a noncancerous (benign) breast condition that occurs when a milk duct beneath the nipple widens and thickens. This can cause the milk duct to become blocked, leading to fluid accumulation and sticky, thick nipple discharge.

It may cause symptoms like tenderness around your nipple area and inverted nipples. Mammary duct ectasia may affect a single breast or both breasts and is more common among women nearing menopause.

Periductal Mastitis

Periductal mastitis is a noncancerous inflammatory breast condition that often occurs in young women who are not breastfeeding. Symptoms include nipple discharge, a breast lump, and breast tenderness.

While the exact cause remains unknown, some clinical evidence suggests obesity, diabetes, bacterial infections, and smoking may cause the condition.

Ductal Carcinoma In Situ

Ductal carcinoma in situ (DCIS) is an early form of breast cancer that affects the cells of the milk ducts in the breast. DCIS doesn't spread outside the breast but should be treated because it can develop into invasive breast cancer that extends beyond the milk ducts.

Although it does not typically come with signs and symptoms, DCIS may cause bloody nipple discharge, a lump, or itching in some people.

Mastitis vs. Clogged Ducts

Most clogged ducts resolve on their own within a couple of days. A prolonged blockage can turn into an infection called mastitis.

Symptoms of mastitis are similar to those of a clogged duct, making it difficult to distinguish between them. However, mastitis is often accompanied by more severe symptoms, including:

  • Redness, warmth, and swelling of the breast (may be wedge-shaped)
  • A painful, red lump in the breast
  • Body aches, nausea, vomiting, chills, and other flu-like symptoms
  • A fever over 100.4 degrees F
  • Yellowish discharge from the nipple

Can Lecithin Help?

Although no significant evidence supports its use, lecithin is thought to help prevent clogged ducts by reducing the viscosity, or "stickiness," of breast milk. Lecithin supplements are generally well-tolerated. However, it's essential to consult a healthcare provider before taking any dietary supplements while breastfeeding.

Home Remedies

The best initial treatment for a clogged duct is to breastfeed often to try to drain the breast as much as possible.

Other remedies to help clear a blocked duct and ease pain and swelling include:

  • Feeding with the affected breast first
  • Positioning your baby with their tongue and chin pointing toward the clogged duct to maximize drainage to the area
  • Massaging your breast gently
  • Applying a heating pad or warm, moist washcloth to the affected breast
  • Soaking your breast in warm water
  • Getting adequate rest
  • Taking over-the-counter (OTC) pain relievers, such as Advil (ibuprofen) or Tylenol (acetaminophen)
  • Avoiding underwire bras or any bra that puts pressure on your breasts
  • Staying hydrated by drinking plenty of water and other clear fluids

How to Massage a Clogged Milk Duct

While feeding or pumping, massage the clogged duct using your hand. To do this, apply pressure behind the affected area with your thumb. Massage gently toward the nipple, focusing on the hardened areas. Continue this massage technique throughout the day, even when you are not nursing.

When to See a Healthcare Provider

If you experience painful, swollen breasts accompanied by chills, body aches, or a fever, contact a healthcare provider as soon as possible. Many cases of mastitis require antibiotics to treat the infection. If left untreated, mastitis may destroy breast tissue, resulting in an abscess that must be drained.

If symptoms continue for seven to 10 days after antibiotic treatment, a healthcare provider may recommend imaging or a biopsy to test for inflammatory breast cancer, which can cause symptoms similar to mastitis.

How Long Can Milk Ducts be Clogged Before Relief ?

While the amount of time varies from person to person, most clogged ducts will resolve independently within 24 to 48 hours, with or without treatment.

Breastfeeding Tips to Completely Empty Milk Ducts

One of the best ways to prevent clogged milk ducts is to ensure your breast is fully drained after each feeding.

Signs of empty milk ducts include:

  • Your breasts will feel softer.
  • You find it difficult to express milk.
  • Your baby is no longer making swallowing and gulping noises.

You can help ensure your breast is drained by feeding your baby or pumping at least eight to 12 times within 24 hours.

Other breastfeeding tips to empty your milk ducts include:

  • Massaging your breasts during feeding to help with milk flow
  • Changing positions frequently to improve breast drainage
  • Ensuring your baby has a good latch during feedings
  • Allowing your baby to come off the breast on their own
  • Using a breast pump or hand expressing after breastfeeding to remove more breast milk


Clogged milk ducts are painful and can make breastfeeding a challenge. In most cases, a clogged duct can be treated at home using simple remedies. However, clogged milk ducts may progress to an infection called mastitis or be a sign of a more severe condition, like breast cancer.

If the lump on your breast changes size or does not go away after a few days, or if you develop a fever, chills, or nausea, it is important to contact your healthcare provider immediately for further evaluation and treatment. 

13 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Lindsey DeSoto, RD, LD
Lindsey Desoto is a registered dietitian with experience working with clients to improve their diet for health-related reasons. She enjoys staying up to date on the latest research and translating nutrition science into practical eating advice to help others live healthier lives.