Caring for the Soft Spot on Your Baby’s Head

As you spend hours gazing at your newborn and stroking their face, you’ll no doubt notice a couple of soft spots on your baby's head. These soft spots, called fontanelles, are perfectly normal and actually play an important role in your baby’s development.

Learn more about these baby soft spots, including how to protect them, when the bones of the skull will harden, and when to worry about your baby's soft spot.

What Are Baby Soft Spots and Where Are They?

All babies are born with two baby soft spots (fontanelles) on their heads: The larger soft spot (anterior fontanelle) is toward the front of the head, and the smaller soft spot (posterior fontanelle) is toward the back.

These softer areas are made up of immature skull bones that are still forming and expanding as your baby’s brain grows.

Why Do Babies Have Soft Spots?

The soft spots on your baby's head have two main functions:

1. They make it possible for the bony plates of the skull to compress and overlap as the head passes through the narrow birth canal during a vaginal delivery.

2. They allow a baby’s skull to expand, making room for the rapid brain growth that happens in the first year.

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Normal vs. Concerning Soft Spot Appearance

Not all changes in your baby’s soft spot are dangerous. Use this guide:

When Does a Baby's Soft Spot Close or Go Away?

In your baby’s first few months, both soft spots should be open and flat. You might ask, when do babies' soft spots go away ? At about 2 to 3 months of age, the soft spot at the back of your baby’s head may close. The soft spot at the front may close around the time your toddler turns 18 months old.

What Happens If You Touch the Soft Spot on Your Baby's Head?

As long as you touch your baby’s soft spots gently—for example, when you’re holding your baby and supporting their head and neck or when you’re washing your baby’s hair—you don’t need to be afraid of hurting them.

There is a thick and durable membrane just under your baby’s scalp that protects their brain, so gently touching the fontanelles won’t hurt them.

To help ensure your baby’s head is protected, it’s a good idea to remind friends, family members, and caregivers to be careful and gentle with your baby’s head.

What Does It Mean When a Baby's Soft Spot Is Pulsating?

Sometimes it may appear that your baby’s soft spot is pulsating. This is completely normal—blood is pulsing through your baby’s body, and this movement can sometimes be visible where the soft spot is. There’s no need to worry if you see your baby’s soft spot pulsing.

What Causes a Sunken Soft Spot on Your Baby’s Head?

A sunken soft spot (also called a sunken fontanelle) is most commonly linked to dehydration in babies. According to the American Academy of Pediatrics (AAP), dehydration can happen when a baby does not get enough breast milk or formula, or when they lose more fluids than they take in—such as during vomiting, diarrhea, fever, or illness.

If your baby isn’t feeding well, you might find it helpful to review a typical baby feeding schedule. Illnesses that cause fluid loss—like vomiting, diarrhea, or a fever in babies—can also increase the risk of dehydration.

Most common causes of a sunken soft spot

In many cases, a sunken soft spot happens when your baby’s body is low on fluids. Common causes include:

• not getting enough breast milk or formula

• fluid loss from vomiting or diarrhea

• fever or other illness.

Less common causes

Occasionally, a sunken soft spot may be related to:

• temporary fluid shifts after sleep

• inadequate nutrition over time.

Most cases improve quickly once the underlying cause is treated and your baby’s fluid balance is restored. Your baby’s healthcare provider can determine what’s going on and guide you on next steps.

Signs of Dehydration to Watch For

A sunken soft spot is often just one clue. Other signs of dehydration may include:

• fewer than six wet diapers in 24 hours (learn more about how often to change a diaper)

• dry mouth or lips

• crying without tears

• sunken eyes

• unusual sleepiness or low energy

• irritability

• cool or blotchy hands and feet

• vomiting or diarrhea.

If you notice several of these symptoms together, contact your baby’s healthcare provider promptly. In young babies, dehydration can become serious quickly, so it’s always safest to have your provider assess your little one.

Keep in mind that a sunken soft spot can sometimes appear even if your baby is not dehydrated. Because every baby is different, it’s important not to try to diagnose the cause yourself. When in doubt, consult your baby’s healthcare provider for reassurance and personalized care.

Treatment for a Sunken Soft Spot

Treatment depends on what’s causing the sunken appearance and how severe dehydration is. In cases of mild dehydration, your baby’s healthcare provider may recommend offering more frequent feeds and monitoring your baby closely at home to make sure symptoms improve.

For moderate dehydration, your healthcare provider might suggest oral rehydration fluids along with adjustments to feeding to help restore fluid balance. In more severe cases, hospital treatment may be necessary so your baby can receive intravenous (IV) fluids to rehydrate quickly and safely.

Most babies recover rapidly once they receive enough fluids and the underlying cause is addressed.

When dehydration or illness is treated:

• the soft spot usually returns to its normal shape

• your baby’s energy improves

• feeding patterns return to normal.

In many cases, improvement happens within hours to a day once hydration is restored.

What Should You Do If Your Baby Hits Their Soft Spot?

You might be wondering what happens if you hit a baby's soft spot. Contact your baby’s healthcare provider if this happens.

If you notice swelling or bulging of the soft spot and/or bruising around their eyes or behind their ears, it may be due to a concussion. Call 911 immediately.

Other signs of a head injury or trauma requiring immediate medical attention include:

• Nonstop crying

• Your baby being unwilling to feed

• Vomiting

• Seizures

• Discharge or blood from ears or nose

• Difficulty waking after sleep.

When Should You Be Concerned About Your Baby's Soft Spot?

For parents, it's crucial to know when to worry about your baby's soft spot. The lack of soft spots on your baby’s head may be a sign of a very rare condition called craniosynostosis, a birth defect in which your baby’s skull bones fuse together earlier than normal, resulting in a misshapen head. Contact your baby’s healthcare provider if:

• Your baby seems to lack soft spots

• There are raised, firm edges where the skull plates meet

• Your baby’s skull shape seems misshapen and is not growing over time.

Seek urgent medical care if your baby has a sunken soft spot along with

• extreme sleepiness or difficulty waking

• refusal to eat

• persistent vomiting

• seizures

• very few wet diapers

• unusual limpness or weakness.

These signs may indicate severe dehydration or another condition requiring prompt treatment.

The Bottom Line

Although it might seem a little odd that your baby would have baby soft spots on their head, they actually serve two important purposes: to make it easier for your baby to pass through the birth canal during a vaginal delivery, and to ensure your baby’s skull can expand to make room for their growing brain.

By around 18 months, your baby’s fontanelles will have closed. In the meantime, be gentle with your baby’s head when holding them.

If your baby accidentally bumps or hits a soft spot, you may wonder what happens if you hit a baby's soft spot. In such cases, contact your child’s healthcare provider right away.

When it comes to the shape of your little one’s head, if you’ve noticed flatter spots, it could be because your little one is spending too much time lying on their back looking the same way. Prolonged pressure on the softer skull bones can flatten out the area. Find out more about flat head syndrome and what you can do to treat or prevent it.