The fragility of a newborn can be one of the most intimidating things in the world. And naturally, you’ll do everything in your power to protect this tiny human from anything that brings worry.

You ever-so-gently lay them down, support their head, dress them lightly, and check every square inch of their body for any unusual signs. And then you notice it: Instead of being perfectly pink, your baby’s tongue looks like it has a white coating on it.

This coating can seem to appear out of nowhere. But here’s the good news — a white tongue in babies isn’t unusual. It’s typically caused by either an overgrowth of yeast — very treatable — or by something as simple as milk residue.

Thrush is a yeast infection caused by an overgrowth of the fungus Candida — yes, the very same type that causes vaginal yeast infections and diaper rashes.

In the case of oral thrush, though, the infection forms on parts of the mouth involved in sucking. This includes your baby’s lips, tongue, and inner cheeks.

And though we know you put baby first, and you second, you should also know that thrush can spread to the object of your baby’s sucking if you’re breastfeeding: your nipples. Conversely, yeast on your nipples (that you may not even know you have) can contribute to thrush in your baby’s mouth.

The tell-tale signs and symptoms of thrush

Not every white tongue is caused by thrush. So here’s a good rule of thumb: If you’re able to wipe or brush off a white coating, thrush isn’t the culprit. Yeast hangs on for dear life.

Also, if your baby has thrush, it’s unlikely for the white to only appear on their tongue. If you open their mouth, you’ll see a cottage-cheese coating over other areas, too, like inside their cheeks.

If you notice these symptoms, don’t panic. But thrush isn’t something to ignore, even if it’s mild and doesn’t seem to cause any problems. There’s always the chance of the infection getting worse, and if it does, your baby may have pain or discomfort that makes it harder for them to feed or latch onto your breast — and if baby’s not happy, no one’s happy.

Causes of thrush

You might wonder why many babies get oral thrush while it’s rarely a problem for adults. The answer is simple: A baby’s young immune system isn’t always strong enough to fight off germs and infections. And because of their weaker immune system, it’s much easier for yeast to grow on some parts of their little body.

But a weak immune system isn’t the only culprit. If your baby takes an antibiotic to treat another infection — say, one of those pesky ear infections — this drug can kill off good bacteria, also encouraging the growth of yeast.

Treatment for thrush

Hearing that your baby has any type of infection can cause a range of emotions. But there’s no need to worry with this one — thrush is very common and easily treatable.

Your baby’s doctor will likely prescribe a liquid antifungal that you’ll apply directly to white patches. For the medicine to work, you’ll want it to sit on their tongue or inside their mouth for as long as possible. So give your baby treatments at least 30 minutes before feedings.

Once the medicine is in their system, you can expect the infection to clear in a few days.

Additional considerations if you’re breastfeeding

To be clear, thrush happens in babies who are bottle-fed and breastfed. If you breastfeed, though, know that it’s possible for you and your baby to spread yeast to each other.

This might be a lesser known problem, but it does happen and it’s called nipple thrush. Signs include:

  • sore, painful nipples after pain-free breastfeeding
  • cracked, itchy, or blistered nipples
  • achy breasts after feedings

If you also have thrush, it isn’t enough to treat your baby. Sure, medicine will clear their infection. But if you don’t clear your own infection, you’ll continue to spread thrush back and forth. There are a lot of things you and baby will share over a lifetime — this shouldn’t be one of them.

Applying a topical antifungal cream — available over the- counter in the form of yeast infection creams and others — on and around your nipples after each feeding is usually enough to kill the fungus.

It’s possible that you might need a prescription antifungal for a particularly stubborn infection. Since yeast likes warm, moist areas, let the skin of your breasts air dry as much as possible before putting your bra back on.

Don’t forget to wash off any leftover residue of the cream before nursing. Your symptoms will also clear up in a few days.

It’s completely normal to worry about your baby. And, honestly, you should never let anyone tell you that your worries are foolish. If you see a white coating on your baby’s tongue, you might immediately think it’s thrush and call the pediatrician — and there’s nothing wrong with that.

But there’s also a chance that what you believe to be yeast is only milk residue.

Distinguishing between the two can be tricky, as they have similar appearances. One of the easiest ways to tell the difference is to try and wipe off the residue with a warm, damp cloth.

If the residue comes off or becomes less noticeable, you’re dealing with milk residue and not thrush. Keep in mind that milk residue is more noticeable after feedings and only appears on the tongue.

What causes this buildup of milk? Simply put, a lack of saliva.

A newborn’s mouth is different from an adult’s mouth in that babies don’t produce a lot of saliva during the first few months after birth. (That is, until they are about 4 months. Then it’s time for a months-long vacay in droolville.) The less saliva, the harder it is for their mouths to wash away milk.

Milk residue may be more likely to occur if your baby has tongue tie, a condition that restricts movement of their tongue. Your baby’s tongue might be unable to touch the roof of their mouth, in which case the lack of friction causes a buildup of milk residue.

This can also happen if your baby has a high palate, and their tongue can’t reach the roof of their mouth.

Regardless of cause, though, milk residue isn’t permanent, nor a reason for concern. A white tongue goes away once your baby’s mouth produces more saliva, or when they start to eat solid foods.

In the meantime, you can consider gently wipe off the residue using a soft, damp cloth after feedings, though this may not be necessary.

Just because thrush is common in babies doesn’t mean you should ignore the problem. Untreated thrush can cause pain and discomfort, and if so, you’ll have a fussy baby on your hands.

See a doctor if your baby develops any creamy, white lesions in their mouth, especially if you can’t remove the whiteness with a damp cloth. It’s likely thrush, but a pediatrician can run tests if they suspect something else.

If your baby has thrush, see your own doctor if your nipples or breasts become sore. It’s important that you’re treated at the same time to stop the spread of the infection.

Gently wiping or brushing your baby’s tongue after each feeding can help prevent a white tongue caused by milk.

As far as thrush goes, your best weapon is to sterilize all equipment used for feedings. This includes bottles, nipples, and your breast pump. You can take it a step further and sterilize pacifiers and any toys your baby puts in their mouth.

If you have thrush on your nipples, prevent recurrent infections by frequently changing your breast pads, and washing your breastfeeding bras in hot water.

Also, if you express or freeze your breast milk with thrush, consider giving this milk to your baby while you’re both being treated. If you give this milk to your baby after the infection clears, there could be a greater chance that the thrush could return.

If you see a white coating on your baby’s tongue, know that it happens and it’s not because you’re doing something wrong. It could be thrush, or it may be something as simple as milk residue.

In the event of thrush, these yeast infections are easily treatable, so see your pediatrician. Your sweet baby will be sticking their perfectly pink tongue out at you before you know it!