A plugged duct happens when inflammation (or swelling) narrows milk ducts in the breast, reducing the flow of milk. Globs of fat in breast milk can clump together and form a plug that gets stuck in the narrowed duct. This can feel like a small lump, sore knot, or hard area in the breast. You won’t have a fever or feel sick, but sometimes the narrowed duct can get worse and lead to an infection.
A plugged duct may happen:

Continue to breastfeed or pump at the rate that has been normal for you when you were not experiencing a plugged duct. Pumping or breastfeeding more often can make a plugged duct worse.

Use gentle massage for a few minutes before and during feedings to help loosen the plug and promote milk flow. Using your fingers, start in front of the plugged area and use gentle circular motions moving toward the nipple. Do not pinch, squeeze, or massage firmly – this can cause more inflammation.

Begin feedings on the side where you feel you have a plugged duct first. Your baby’s stronger initial sucking can help loosen the plug and keep milk moving freely.

Try different feeding positions. Changing positions can change the suction in different areas of the breast.

Apply ice or cold packs to reduce pain and swelling. Use the cold pack for 10 to 15 minutes at a time, several times a day. Help protect your skin by placing a thin cloth between the ice pack and your breast.

Stay well-hydrated with water and rest as much as possible.

Wear a well-fitting, supportive bra that doesn’t put pressure on your breasts.

Use warm compresses cautiously before feeding, as brief warmth (about 5 to 10 minutes) can encourage milk flow, but avoid heat if your breasts are already inflamed, as this could make swelling worse.

Ask your healthcare provider about medicine to help with pain and swelling, like acetaminophen (Tylenol) or ibuprofen (Motrin). A lecithin supplement may help to treat and prevent plugs as well. Ask your doctor about the safest options for you.
If the plug doesn’t resolve or get smaller in size within 24 hours, ask for help from a lactation consultant or healthcare provider. Plugged ducts can sometimes lead to an infection of the breast, called mastitis, which may require medical attention. Learn more about mastitis.