Thrush While Breastfeeding: Signs in Baby and You, and What Helps

Thrush is a common yeast infection in young babies, and because breastfeeding brings your baby’s mouth and your nipples into close contact, it can affect you both. The good news: it’s treatable, and you can keep breastfeeding through it.

Thinking about thrush has also changed in recent years. Burning nipples and deep, shooting breast pain used to be blamed on yeast almost automatically. Research now suggests that’s often not the cause. Here’s how to recognize thrush, how it’s usually treated and what to check if the pain isn’t fitting the pattern.

What causes thrush?

Thrush is an overgrowth of Candida albicans, a yeast that normally lives on skin and in the mouth and gut in small amounts. Babies are prone to it because their immune systems are still developing. Antibiotics (for you or your baby) can also tip the balance, because they reduce the bacteria that normally keep yeast in check.

Signs of oral thrush in your baby

According to MedlinePlus and the NHS, look for:

• White, velvety or cottage-cheese-like patches on the tongue, inner cheeks, gums or lips
• Patches that don’t wipe off easily and may bleed slightly if you try
• Redness inside the mouth
• Fussiness at the breast, pulling off or refusing to feed because the mouth is sore
• A diaper rash that doesn’t clear with usual barrier creams (yeast can affect the diaper area too)

Some babies have thrush with no symptoms at all.

A plain white tongue isn’t the same as thrush. A thin milky coating that wipes away easily is normal in breastfed babies.

Signs of yeast on your nipples

MedlinePlus lists deep-pink, cracked or sore nipples and pain during and after feeds. Other commonly described signs include itchy or burning nipples and shiny or flaky skin on the nipple or areola.

These symptoms are not specific to yeast, though. A shallow latch, eczema or dermatitis, bacterial infection, a milk bleb and nipple vasospasm (a blanching, burning pain when blood vessels tighten) can all look similar. La Leche League GB suggests ruling out these more common causes first. Our guide to sore and cracked nipples explains the latch-related ones.

Treatment: why both of you may need it

If both you and your baby have thrush, MedlinePlus advises treating you both at the same time. Otherwise the yeast can keep passing back and forth during feeds.

For your baby

Mild thrush sometimes clears on its own within a few days. When treatment is needed, a provider usually prescribes an antifungal liquid or gel that’s applied inside the baby’s mouth, often after feeds. Nystatin oral suspension is a common choice for young babies. Don’t use over-the-counter mouth gels on a baby without checking with your pediatrician first: the NHS advises seeing a doctor for any baby under 4 months with signs of thrush, and some gels aren’t recommended for young infants because of a choking risk.

For you

For nipple thrush, providers typically recommend a topical antifungal cream. LactMed, the NIH database on medicines and breastfeeding, notes that nystatin is barely absorbed into the body and is considered acceptable while breastfeeding, including on the nipples. It advises using water-based creams or gels rather than ointments and wiping off any excess before feeds. Your provider may prefer a different antifungal, such as miconazole or clotrimazole cream.

Always check the product, dose and length of treatment with your doctor, pharmacist or IBCLC, and finish the full course even if symptoms improve. If you’re not better after about a week of treatment, go back to your provider rather than just continuing.

What the evidence says about “ductal thrush”

You may read that yeast can get inside the milk ducts and cause deep, stabbing breast pain, sometimes called ductal or mammary candidiasis. The evidence for this is weak:

• A 2017 study in PLOS ONE examined milk, nipple swabs and biopsies from more than 500 women with symptoms blamed on breast yeast. The authors concluded that yeast’s role in breast and nipple pain is marginal at most, and that bacteria (mainly staphylococci and streptococci) were the more likely cause. They suggested calling the problem subacute mastitis instead.
• The Academy of Breastfeeding Medicine’s 2022 Protocol #36 states that no scientific evidence supports the diagnosis of “candida mastitis.”
• La Leche League GB notes that a positive swab doesn’t prove infection, because Candida normally lives on skin, and that relief from antifungal creams may come from their anti-inflammatory effects.

This doesn’t mean nipple thrush never happens, especially when your baby clearly has oral thrush. It does mean that deep breast pain on its own deserves a proper assessment, because the real cause may be inflammation, bacteria or a latch problem that needs different treatment. If a firm, painful area develops in your breast, read about mastitis and when to see a doctor.

Hygiene that helps

The NHS suggests, while you and your baby are being treated:

• Wash your hands after diaper changes and before and after feeds or applying cream.
• Wash bras, breast pads, bibs and burp cloths on a hot cycle, and change breast pads often.
• Sterilize pacifiers and bottle parts regularly.
• Replace bottle teats and nipple shields weekly.
• Don’t freeze breast milk to use later while your baby has oral thrush.

Advice on heavy sterilizing varies. The ABM advises against routinely sterilizing pump parts or toys to get rid of yeast, so ask your provider what’s needed in your situation.

When to call a doctor or lactation consultant

Contact your baby’s doctor or your own provider if:

• Your baby has signs of thrush, especially if under 4 months old
• Your baby is refusing feeds, feeding much less or has fewer wet diapers
• Thrush isn’t improving after about a week of treatment, or keeps coming back
• You have nipple or breast pain that lasts beyond the first weeks or worsens
• You have a fever, flu-like symptoms or a red, painful area in your breast

A lactation consultant can watch a feed and help sort out latch-related pain from infection. Find help on our breastfeeding support page, or browse more guides in our Common challenges hub.