Babies can develop suck blisters due to friction when feeding. They can also get cold sores if they’ve been exposed to the virus that causes them and may experience other symptoms.

Most likely, until you became a parent, the only blisters you worried about were the ones caused by a pair of shoes you knew weren’t a great fit but bought anyway.

Welcome to the world of blisters on your baby’s lip. These tiny bumps and marks might look a little scary, but rest assured, they’re often completely normal and nothing to worry about.

Your little one may develop a blister on their lips for a couple of reasons.

Babies suck (we mean that in the best possible way)

Blame it on friction: Most lip blisters in newborns are caused by the vigorous sucking they engage in to fill their tummies. These blisters may also be known as:

  • suck blisters
  • friction blisters
  • suck callouses

Babies begin to practice their sucking reflex while in the womb, and one 2013 case study even reported a baby born with these blisters.

In short, don’t be surprised if your little one gets a blister or two on their lips — it’s normal.

While lip blisters are more common in breastfed babies, bottle-fed babies can also get them.

So, what do lip blisters look like?

You might see:

  • a slight swelling on your baby’s upper lip — you might not even really be sure it’s there
  • a little peeling of their lip, sort of like when your lips get chapped
  • a single blister smack in the middle of their upper lip

More rarely, you’ll notice rows of blisters. Sometimes these can appear on both your baby’s top and bottom lip, and they may not be so noticeable unless their lips are open.

Lip blisters usually appear in the early days after birth, when babies are sucking every 3 hours or more. The good news is they usually disappear on their own.

Do they hurt? Nope. In fact, lip blisters may even help make your baby a more efficient feeder. That’s because the toughened skin may make it easier for them to latch on.

But here’s the catch: Blisters that don’t disappear could be a sign of a latching issue. If your baby doesn’t latch on correctly, they may compensate by using their lips to hold on to your breast.

And that equals persistent blisters.

If your little one continues to get blisters beyond the first few weeks, it’s important to address their latch, as we’ll discuss later.

Cold sores (another reason for lip blisters)

Cold sores are so common that most of us have probably suffered from one at some point. Remember those small whitish, pinkish, reddish blisters that appear around your mouth and on your lips?

While cold sores are common in adults and older kids, they’re not that common in babies who haven’t been exposed to the world yet.

But they can be passed to your baby if someone with the virus comes in contact with them. This is why it’s totally OK to discourage others from kissing your baby’s face and hands.

If you do spot a cold sore on your baby’s lips, it’ll most likely heal on its own within 1 or 2 weeks. Sometimes, though, cold sores in babies can lead to unpleasant health complications.

It’s important to talk to your baby’s doctor right away if you notice these three things:

  • you see a cold sore on your baby’s lip
  • your baby has fever
  • your baby isn’t feeding with their normal gusto

Treating a friction or suck blister on your baby’s lip involves a two-pronged approach: establish a good latch and encourage healing.

Tips to establish a good latch

  • Tickle your baby’s lip with your nipple to encourage them to open their mouth widely when latching. This could take a few tries. Patience — they’re still learning.
  • When you see that baby’s mouth is wide open, with their chin lowered and tongue down, you can ease your breast into their mouth. Aim your nipple toward their nose.
  • Try to get as much of the lower part of your areola into their mouth as possible. No go? Try again. It’s a learning curve.

With a deep latch and your breast further back in your baby’s mouth, their tongue (and not their lips) can do most of the milking action. This will help prevent additional blisters from forming.

Several things could make it hard for your baby to latch on well. Here’s what to look out for:

  • If your baby is tongue-tied, they won’t be able to raise their tongue sufficiently to cover the lower gumline and work against your breast.
  • If your baby is lip-tied, their lip won’t have the range of movement necessary to get your breast far enough into their mouth.

Either way, your baby will grasp your breast or nipple with their gums and lips. The result? A long-term sucking blister.

Also, don’t expect preemies to be ready to feed yet. They’ve still got some growing to do.

Their brains aren’t sufficiently developed, so they’re lacking the neurological backing. Plus, they’re missing the fat pads in their cheeks that support their tongue while milking.

If your bottle-fed baby is developing suck blisters, their latch can also be addressed:

  • Consider your feeding position. Make sure baby is able to take the bottle nipple fully into their mouth and isn’t straining to hold on to it with their lips.
  • Experiment with paced feeding to allow for a comfortable suck speed.
  • Check that the nipple size is appropriate for their age and development.

Tips to encourage healing

Here are a few things that may help a lip blister heal:

  • Breast milk. Your breast milk is chock-full of hundreds to thousands of nutrients, fats, and vitamins primed to nurture and heal. For example, immunoglobulin A is a blood protein that contains bacteria to fight off infection, and palmitic acid is a super moisturizer. Dab a few drops of breast milk onto your baby’s lips to lower the risk of infection as well as to soothe and moisturize them.
  • Natural oils. Rub a few drops of olive oil or coconut oil onto your baby’s lips for an effective moisturizer.
  • Lanolin cream. You may already be using this to treat your nipples. A slight smear on your baby’s lips can help treat a lip blister, too.

If you thought that being a baby is all bliss, now you know it’s actually all relative. Your little one may be plugging away so hard they blister their lip.

And now that you’ve solved another child-rearing mystery, feel free to take a well-deserved break.