How to Check Your Baby's Soft Spot for Hydrocephalus
At a Glance
To check your baby's soft spot for signs of hydrocephalus, gently feel it when they are completely calm and held upright. A healthy soft spot feels flat and soft. If it feels firm and tense like an inflated balloon, it may indicate dangerous fluid pressure requiring immediate medical care.
To correctly check your baby’s anterior fontanelle (the soft spot on the top of their head) for signs of dangerous pressure, always gently feel it when your baby is completely calm and sitting upright [1]. A soft spot that feels very firm and tense—like a fully inflated balloon—can be a warning sign that fluid is building up in their brain [1].
Is it Safe to Touch the Soft Spot?
Many parents worry about hurting their baby by touching the fontanelle. Rest assured that gently feeling or pressing the soft spot with the flat pads of your fingers is completely safe. A thick, tough membrane protects the brain, so your gentle touch will not cause any harm. Note that this assessment is only useful while the soft spot is open; the anterior fontanelle typically closes on its own between 9 and 18 months of age.
The Right Time and Position to Check
When babies cry, cough, or strain, the pressure inside their head naturally goes up, which can temporarily make their soft spot bulge outward [1]. Similarly, when a baby is lying flat on their back, gravity can cause the fontanelle to look fuller than normal [1]. Because of this, checking at the wrong time can cause unnecessary panic.
To get an accurate assessment:
- Wait until your baby is completely calm, relaxed, or even asleep [1].
- Hold your baby in an upright, vertical position [1].
Note: If your baby is inconsolably irritable and cannot be calmed down, do not wait for them to calm down to check the soft spot. Extreme irritability is a warning sign of high pressure on its own, and you should seek medical care immediately [2].
What Does a Normal Soft Spot Feel Like?
When a baby is upright and relaxed, a healthy fontanelle usually feels flat or even slightly curved inward (concave) [1]. It will feel soft to the touch, and you might even be able to see or feel a gentle pulsing rhythm that matches your baby’s heartbeat.
What Does a Dangerously Bulging Soft Spot Feel Like?
If there is a dangerous buildup of cerebrospinal fluid (CSF)—whether due to untreated hydrocephalus, a blocked shunt, or a failing Endoscopic Third Ventriculostomy (ETV)—the extra pressure pushes against the skull from the inside.
A pathologically bulging fontanelle will typically feel:
- Tense and firm: It will resist your touch and feel tight, similar to how a fully blown-up balloon feels when you press on it [1].
- Constantly raised: The bulge will remain prominent even when the baby is completely calm and held upright [1].
When to Seek Immediate Medical Attention
While a tense, bulging fontanelle is a classic indicator of increased intracranial pressure, it is not the only sign. In some cases, dangerous pressure can build up even if the fontanelle does not appear severely swollen [3]. You should contact your neurosurgeon or seek emergency medical care if you notice a firm, bulging soft spot, especially if it is accompanied by other warning signs:
- Unusual, extreme sleepiness (lethargy) or difficulty waking up [2]
- Persistent, forceful vomiting (more than just normal infant spit-up) [2]
- Extreme irritability or a high-pitched cry [2]
- Sunsetting eyes: When the eyes appear driven downward, making the white part of the eye highly visible above the colored part [2].
Common questions in this guide
Is it safe to touch my baby's soft spot?
What is the best position to check my baby's fontanelle?
What does a normal baby soft spot feel like?
What does a dangerously bulging fontanelle feel like?
At what age does a baby's soft spot normally close?
Questions to Ask Your Doctor
Curated prompts to bring to your next appointment.
- 1.At what age do you expect my baby's soft spot to fully close, and how should we monitor for pressure changes after that happens?
- 2.If I am unsure whether the soft spot feels dangerously firm, what is the fastest way to get guidance from the care team?
- 3.Are there any other physical signs on my baby's head, such as swollen veins, that I should be watching for alongside the fontanelle?
Questions For You
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References
References (3)
- 1
A comprehensive review of the anterior fontanelle: embryology, anatomy, and clinical considerations.
D'Antoni AV, Donaldson OI, Schmidt C, et al.
Child's nervous system : ChNS : official journal of the International Society for Pediatric Neurosurgery 2017; (33(6)):909-914 doi:10.1007/s00381-017-3406-1.
PMID: 28396968 - 2
The relation of optic nerve sheath diameter (ONSD) and intracranial pressure (ICP) in pediatric neurosurgery practice - Part I: Correlations, age-dependency and cut-off values.
Kerscher SR, Schöni D, Hurth H, et al.
Child's nervous system : ChNS : official journal of the International Society for Pediatric Neurosurgery 2020; (36(1)):99-106 doi:10.1007/s00381-019-04266-1.
PMID: 31256241 - 3
Shunt surgery for early-onset severe hydrocephalus in methylmalonic acidemia: report on two cases and review of the literature.
Ma M, Wu M, Li Y, et al.
Child's nervous system : ChNS : official journal of the International Society for Pediatric Neurosurgery 2018; (34(7)):1417-1421 doi:10.1007/s00381-018-3753-6.
PMID: 29488077
This page provides educational information on checking your infant's soft spot for signs of hydrocephalus. It does not replace professional medical advice. Seek immediate emergency care if your baby is inconsolable, vomiting, or showing signs of high intracranial pressure.
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