Engorgement, blocked ducts and mastitis: what to do

Short answer: Engorgement means both breasts feel very full and tight, often when your milk comes in. A blocked duct is a tender lump in one area. Mastitis is when part of the breast becomes swollen, hot and painful, often with flu-like symptoms. In all three, keep breastfeeding when your baby wants, check positioning and attachment, use cold compresses for pain, rest and take paracetamol or ibuprofen if needed. Don't massage hard or express more than your baby needs. See a GP if you're not improving within 12 to 24 hours.

You notice a hard, sore spot in your breast. A few hours later you feel shivery and achy, as if you're getting flu. That's the moment to act, not to wait and see.

Three things that can look alike

Engorgement

Your breasts feel overly full, hard, tight and painful, usually in the first days as your milk comes in, or when your baby hasn't fed for a while. It can make the nipple flatter and harder for your baby to latch onto.

A blocked duct

A small, tender lump in one part of the breast, often because that area isn't being drained well during feeds. You usually feel otherwise well.

Mastitis

Mastitis usually affects one breast and can come on quickly. Signs include a swollen area that feels hot and painful to touch (redness can be harder to see on black or brown skin), a wedge-shaped lump or hard area, burning pain, and flu-like symptoms such as aches, a high temperature, chills and tiredness.

The key questions: do you feel feverish and unwell, and is one area hot and painful? Then it's more than ordinary fullness.

What helps

  1. Keep breastfeeding when your baby wants and for as long as they want. Don't stop suddenly. Your milk is safe for your baby.
  2. Check positioning and attachment. Poor attachment is a common cause. A midwife, health visitor or breastfeeding specialist can watch a feed.
  3. Offer the sore side, but don't let the other breast get overly full.
  4. If feeding is too painful, or your baby won't feed from that side, hand express — but only as much as your baby would usually take. Expressing extra can increase your supply and make things worse.
  5. Use a cold compress (a cloth soaked in cold water) on the sore area for about 10 minutes every hour to ease pain and swelling. A little warmth just before a feed or expressing can help milk flow; avoid lots of heat.
  6. Be gentle. Don't press hard or massage deeply; any pressure should be light.
  7. Take paracetamol or ibuprofen for pain or a high temperature. Don't take aspirin.
  8. Rest, wear a comfortable, supportive bra, and avoid tight clothing. Don't apply oils, soaks or creams to the breast.

When to see a GP

  • Your symptoms don't improve 12 to 24 hours after treating them at home.
  • You've been given antibiotics and aren't better after 48 hours.
  • You have mastitis symptoms and aren't breastfeeding.

A GP may prescribe antibiotics that are suitable while breastfeeding. A very small amount may pass into your milk; this isn't harmful, though it can make some babies a little unsettled.

Get urgent help

Ask for an urgent GP appointment or call NHS 111 (or your local equivalent) if you have a painful, warm or red breast with a lump or swelling that isn't settling. Occasionally an infection forms a breast abscess — a painful collection of pus — which needs hospital treatment. If you feel very unwell, confused, or have a racing heart or fast breathing, call 999 (UK), 911 (US) or 112 (EU).

Preventing it from coming back

  • Feed responsively and avoid long gaps, especially in the early weeks.
  • Get help with positioning and attachment early — repeated mastitis is often linked to this.
  • Avoid tight bras and anything that presses on the breast, such as a bag strap.
  • Reduce feeds gradually if you're stopping or adding formula, rather than all at once.

In the UK, the National Breastfeeding Helpline is open 24 hours a day on 0300 100 0212.

Mastitis is a common reason people stop breastfeeding earlier than they wanted. Getting help quickly often means it doesn't have to be.

Related reading

Breastfeeding support: Breastfeeding with Confidence (PDF, English) takes you step by step through common breastfeeding challenges.

Sources

  1. NHS — Mastitis.
  2. NHS — Breast pain and breastfeeding.
  3. NHS — Breast abscess.

Written by the Bloom Guides editorial team. Last updated: 19 October 2026. General information only — not a substitute for advice from your midwife, health visitor or doctor.

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