Your Baby's Soft Spot: What's Normal, Sunken or Bulging
A baby’s soft spot should feel firm and curve very slightly inward, and seeing it pulse gently with her heartbeat is normal. It can puff up while she cries, strains or lies down, and that’s normal too, as long as it settles once she’s calm and held upright. Two changes are not normal. A clearly sunken soft spot can mean dehydration. One that stays tense or bulging while she’s calm and upright needs emergency care, especially with fever or unusual sleepiness. Here’s how to read it without poking at it every hour.
What the soft spot actually is
A newborn’s skull isn’t one bone yet. The AAP explains that the bones are “soft bony plates that are capable of compressing and overlapping” so the head can fit through the birth canal. Where the plates meet, there are gaps covered by a tough membrane. These are the fontanelles, and they give the brain room to grow fast through the first year.
Most parents notice two:
- The front one (anterior fontanelle): the larger spot on top of the head, the one people mean by “the soft spot.”
- The back one (posterior fontanelle): smaller, toward the back of the head, and often hard to find at all.
The AAP describes the larger one as front and the smaller as “typically less noticeable.” If you can only find one, that’s usually why.
What normal looks and feels like
MedlinePlus says the fontanelles “should feel firm and very slightly curved inward to the touch.” Flat to slightly dipped, smooth and firm, is what you’re looking for when she’s calm and upright.
It pulses. This one alarms a lot of parents. The AAP’s answer: when the soft spot “may seem to be pulsating. There is no need to worry—this movement is quite normal and simply reflects the visible pulsing of blood that corresponds to your baby’s heartbeat.” It’s easiest to see in babies with fine or little hair.
It bulges when she cries. MedlinePlus says that “when the infant is crying, lying down, or vomiting, the fontanelles may look like they are bulging. However, they should return to normal when the infant is in a calm, head-up position.” So a raised soft spot mid-scream tells you nothing. Check it again once she’s settled against your shoulder.
You can touch it. The AAP says that despite having no bony layer, the soft spots “are well protected from typical day-to-day baby handling.” Washing her hair, brushing it and stroking her head are all fine. Normal handling won’t hurt the soft spot.
Her head shape may be odd at first. The AAP calls slightly misshapen heads “quite common right after birth,” with ridges you can feel where the plates overlapped. Over the next several weeks the head usually rounds out.
When does the soft spot close?
MedlinePlus gives the usual ranges:
- the back one “most often closes by age 1 to 2 months”
- the front one “most often closes within 7 to 19 months”
That’s a wide window, and early or late within it is ordinary. If you’re curious where your baby is, ask at her next well-baby visit.
A sunken soft spot
A noticeably sunken soft spot is, in MedlinePlus’s words, “a sign that the infant does not have enough fluid in their body,” and it “can be a medical emergency. A health care provider should check the infant right away.”
The AAP adds useful context: on its own, a slight dip “can be a subtle finding or sometimes be present in normal babies.” What makes it meaningful is what comes with it. In young babies, the AAP says, a sunken soft spot “when combined with poor feeding and dry diapers” can suggest dehydration. The NHS lists it with other dehydration signs in babies: sunken eyes, few or no tears, fewer wet diapers than usual, and being drowsy or irritable.
So look at the whole baby, not just her head:
- Is she feeding as usual, or refusing or tiring quickly?
- Are wet diapers dropping off?
- Is her mouth dry? Is she unusually sleepy or hard to wake?
If the soft spot is clearly sunken and any of those are true, get her seen right away. If the soft spot looks fine but feeding or diapers worry you, trust that too. The feeding signs and diaper counts are in is my newborn eating enough. If she’s bringing milk back up, spit-up versus vomit helps you tell which one you’re dealing with.
A bulging soft spot
The test is simple: hold her upright and wait until she’s calm. MedlinePlus says that if the fontanelle “returns to normal appearance when the child is calm and head-up, it is not a truly bulging fontanelle.”
A truly bulging fontanelle stays raised, tense or firm when she’s calm and upright. MedlinePlus says this needs “immediate, emergency care,” “especially if it occurs along with fever or excess drowsiness.” It can signal raised pressure inside the skull, including from infections such as meningitis. The AAP’s newborn illness checker likewise lists a soft spot that “looks swollen” as a reason to call the doctor or get care now.
The company it keeps matters here too. A tense soft spot with fever, vomiting, floppiness, a weak or strange cry, or a baby who is hard to wake is an emergency at any hour. Stiffening and arching with a bulging soft spot is one of the urgent rows in baby arching her back.
When to call
Call 911 or go to the ER now:
- the soft spot stays tense or bulging while she is calm and upright, especially with fever or unusual drowsiness
- a clearly sunken soft spot with a dry mouth, very few wet diapers, or a baby who is hard to wake
- she can’t be woken, is floppy, or is breathing with effort
Call the pediatrician today:
- the soft spot looks more sunken than usual and she’s feeding less
- a fever of 100.4°F (38°C) or higher in a baby under three months (urgent, any hour)
- anything about her head shape or soft spot that worries you
FAQ: the baby soft spot
Is it normal for a baby’s soft spot to pulse?
Yes. The AAP says a pulsing soft spot is “quite normal” and simply shows the blood flow that matches her heartbeat.
Is it normal for the soft spot to bulge when crying?
Yes. It can look raised while she cries, strains, lies down or vomits. It should go back to normal once she’s calm and upright. If it stays raised, that’s urgent.
What does a sunken soft spot mean?
It can be a sign of dehydration, especially with poor feeding, dry diapers or a dry mouth. A clearly sunken soft spot should be checked right away.
When does a baby’s soft spot close?
The back one usually closes by 1 to 2 months. The front one usually closes between 7 and 19 months.
Can I hurt my baby’s soft spot by touching it?
No. The AAP says it is well protected from everyday handling, so washing and stroking her head are fine.
