That soft area on a baby's head, where it feels like there's no bone at all, is one of the most nerve-wracking things to touch for the first time. It's called the soft spot — or fontanelle, the clinical name — and even though it looks delicate, it serves an important purpose and is rarely a cause for alarm.
What it is (and why it's called a "soft spot")
It's the gap between skull bones that haven't fully joined yet. They're there for two reasons: they let the baby's head narrow slightly to pass through the birth canal, and they leave room for the brain to keep growing quickly during the first year. There are two main ones: the anterior fontanelle (larger, diamond-shaped, on top of the head) and the posterior one (smaller, triangular, at the back).
What's normal to see
- Noticing a slight pulse is normal — it's the baby's own pulse coming through that thinner area.
- To the touch it's firm but flexible, not hard like the rest of the skull.
- A slight concavity (looking a bit sunken) is normal, especially with the baby calm and sitting up.
When to worry
- It looks very sunken, along with dry mouth, fewer wet diapers than usual, or lethargy — could be dehydration.
- It's bulging and firm even with the baby calm and sitting up (not just while crying, which is normal for a moment) — could indicate increased pressure inside the skull, seek care urgently.
- The anterior one closes before 3 months, or is still open past age 2.
Basic care
It's completely fine to touch, brush hair over, and wash it as normal — there's no need to avoid that area. Even though it looks vulnerable, a tough membrane protects the brain underneath, and everyday contact (brushing hair, washing, resting the head while sleeping) poses no risk.
Growth curve — a real screen from the Alfonso app.
Log checkups and track the progress
Create your baby's profile in 30 seconds, no account or password needed, and note every pediatrician checkup — to keep a clear record that everything is developing as expected. Syncs automatically with your partner.
Frequently asked questions
Is "soft spot" the same as fontanelle?
Yes — "soft spot" is the everyday name, "fontanelle" is the clinical one.
Is it normal for it to look sunken?
Slightly, yes, especially when calm. Very sunken with other signs can mean dehydration.
When does it close?
The posterior one between 2-3 months, the anterior one between 9-18 months.
Keep reading
ℹ️ This article is informational and doesn't replace a pediatrician's judgment. If you're unsure about your baby's soft spot, always check with a healthcare professional.