When Does Milk Come In? What to Expect

The Office on Women's Health says it is normal for the breasts to become larger, heavier, and a little tender when they begin making milk. ¹ The American Academy of Pediatrics adds that a little fullness during the first few days after birth is normal. ² Below is what recognised health bodies say about when milk comes in, what the fullness feels like, and how to ease it, quoted and linked.

Key takeaways

• The Office on Women's Health says the breasts becoming larger, heavier and a little tender when they begin making milk is normal. ¹
• The Office on Women's Health says engorgement usually happens on the third to fifth day after birth, but it can happen at any time. ¹
• The NHS says early engorgement can be due to your milk coming in. ³
• The NHS says to feed your baby often to ease the discomfort. ³

**A quick, honest note:** we're not medical professionals - everything here was researched by us from the public sources listed at the bottom of this page, and it isn't professional advice. Read our full note ↓

When does milk come in, and what does it feel like?

La Leche League explains the mechanism: a few days after birth, hormones shift and the blood supply to the breasts increases to start milk production, causing fullness. ⁴ It adds that if you have had IV fluids, that fullness may be more than normal. ⁴ The Office on Women's Health says it is normal for the breasts to become larger, heavier, and a little tender when they begin making milk, ¹ and the American Academy of Pediatrics says a little fullness during the first few days after birth is normal. ²

The NHS says breast engorgement is when the breasts become overly full, ³ and that in the early days engorgement can be due to your milk coming in. ³ The Office on Women's Health says that when fullness turns into engorgement, the breasts feel very hard and painful. ¹ On timing, it says engorgement usually happens during the third to fifth day after birth, but that it can happen at any time - especially with an oversupply of milk or when feedings or expressing are missed. ¹

How do you ease the fullness?

The NHS says to feed your baby often to ease the discomfort. ³ If the breast is too firm for the baby to latch, La Leche League says hand expressing before nursing can soften the area around the nipple so the baby can latch, ⁴ adding to do any pressing gently and for a short time, because nothing you do to your breasts should hurt. ⁴ The Office on Women's Health says to hand express or pump a little milk before breastfeeding and to use cold compresses between feedings. ¹ The NHS adds an important limit on any expressing: it says to express only enough to relieve the discomfort, because expressing more will make you produce more milk. ³

The American Academy of Pediatrics says excessive engorgement can occur from missed feedings or a change in how often the baby nurses, and that it can also decrease your milk supply. ²

When should I get help?

The NHS says to ask your midwife, health visitor or a breastfeeding specialist for advice immediately to help relieve the engorgement and prevent it happening again. ³

Frequently asked questions

When does breast milk come in?

La Leche League says a few days after birth, when hormones shift and blood supply to the breasts increases. ⁴

What does it feel like?

The Office on Women's Health says the breasts become larger, heavier and a little tender; if it turns into engorgement they feel very hard and painful. ^{1 1}

How do I ease it?

The NHS says to feed often, and if you express, express only enough to relieve discomfort, because expressing more makes you produce more. ^{3 3}

When should I get help?

The NHS says to ask a midwife, health visitor or breastfeeding specialist for advice immediately. ³

A note from us

We're the team behind Yael & Michal. We are not doctors, nurses, lactation consultants, or psychologists, and nothing here is professional advice.

Everything above was researched by us from public, reputable sources - we name and link every one of them below - and summarized as carefully as we could, as a free resource for other mothers. We do this because we wished something like it had existed for us.

When we name an organisation such as the CDC, the NHS, La Leche League, or the Israeli Ministry of Health, we are only citing their published guidance; it does not mean they endorse, sponsor, approve, or are affiliated with us. They have no involvement with this site, and we never use their logos or seals.

Yael & Michal sells nursing bras, which are comfort garments and not medical devices; we do not claim they prevent, treat, or cure any medical condition. The health information here is written for you as a free resource - it is separate from anything we sell.

We try hard to get it right, and we cite our sources so you can check us. But we are not a medical authority, and this cannot replace talking to a professional who knows you and your baby. Please check anything that matters with your doctor, midwife, or an IBCLC lactation consultant. This content has not been reviewed by a medical professional. Reading this site does not create a doctor-patient relationship, or any other professional relationship, between you and us.

If something feels urgent, contact your healthcare provider or emergency services.

Read our full Medical Disclaimer · How we research and write · Content Terms

Sources

1. Office on Women's Health (womenshealth.gov). https://womenshealth.gov/breastfeeding/breastfeeding-challenges/common-breastfeeding-challenges (retrieved 2026-07-10).
2. HealthyChildren.org (American Academy of Pediatrics). https://www.healthychildren.org/English/ages-stages/baby/breastfeeding/Pages/Engorgement.aspx (retrieved 2026-07-10).
3. NHS (nhs.uk). https://www.nhs.uk/baby/breastfeeding-and-bottle-feeding/breastfeeding-problems/breast-pain/ (retrieved 2026-07-10).
4. La Leche League International (llli.org). https://llli.org/breastfeeding-info/engorgement/ (retrieved 2026-07-10).