Bulging Fontanelle (Soft Spot) in Babies

Content reviewed against published AAP, MedlinePlus, NHS guidelines

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A bulging fontanelle is when the soft spot on the top of a baby's head appears to be swelling outward or feels tense and firm when the baby is upright and calm. While brief bulging during crying or straining is normal, a persistently bulging fontanelle can indicate increased intracranial pressure and requires prompt medical evaluation.

Key takeaways

  • A bulging fontanelle is when the soft spot on the top of a baby's head appears to be swelling outward or feels tense and firm when the baby is upright and calm.
  • Most common cause: Crying or straining (temporary, resolves when calm)
  • Emergency: Fontanelle is bulging and baby has fever
  • Home care: Check fontanelle when baby is calm and in an upright position for accurate assessment

Possible Causes

Crying or straining (temporary, resolves when calm)common
Vomiting or coughing (temporary)common
Meningitis or encephalitisuncommon
Hydrocephalus (fluid buildup in the brain)uncommon
Intracranial hemorrhagerare
Brain tumorrare
Hypervitaminosis A (excess vitamin A)rare

When to Seek Help

Emergency — Call 911 or go to ER:

  • Fontanelle is bulging and baby has fever
  • Bulging fontanelle with seizures
  • Bulging fontanelle with inconsolable high-pitched crying
  • Bulging fontanelle with vomiting and lethargy
  • Bulging fontanelle after a head injury or fall
  • Baby is unresponsive or extremely difficult to wake with bulging fontanelle

Urgent — See doctor today:

  • Fontanelle appears consistently full or tense when baby is calm and upright
  • Rapid increase in head circumference
  • Baby has bulging fontanelle with poor feeding or unusual irritability
  • Eyes appearing to deviate downward (sunset sign)

Same-day appointment:

  • Fontanelle seems slightly fuller than usual but baby is acting normally
  • Mildly tense fontanelle with no other symptoms

Monitor at home:

  • Fontanelle bulges only during crying or straining (this is normal)
  • Slight pulsation visible at the fontanelle (this is normal)

By Age

0-3 months

Normal: The anterior fontanelle is typically soft and flat or slightly concave when baby is upright and calm. It may pulse slightly with heartbeat. It commonly bulges during crying.

Worry if: Fontanelle remains bulging when baby is upright and calm, especially if accompanied by fever, vomiting, irritability, or lethargy. Seek emergency care immediately.

3-6 months

Normal: Fontanelle is still open and soft. Slight pulsing remains normal. Brief bulging with straining or lying flat is expected.

Worry if: Persistent bulging with fever, high-pitched crying, excessive sleepiness, vomiting, or seizures. Rapid head growth (crossing percentile lines).

6-12 months

Normal: Fontanelle begins to gradually get smaller. Still normally soft and flat when baby is calm and upright.

Worry if: Fontanelle that becomes tense or bulging, especially with irritability, poor feeding, vomiting, or abnormal eye movements (sunset sign).

1-2 years

Normal: Anterior fontanelle typically closes between 12-18 months. Some close as late as 24 months and this can be normal.

Worry if: Bulging fontanelle at this age is more concerning and always warrants prompt medical evaluation, particularly with any neurological symptoms.

Home Care

  • Check fontanelle when baby is calm and in an upright position for accurate assessment
  • Know that brief bulging during crying, coughing, or straining is normal
  • Keep track of head circumference measurements at well-child visits
  • Note any changes in feeding patterns, alertness, or behavior
  • Do not press hard on the fontanelle — gentle touching will not harm the baby

Need help deciding what to do?

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Frequently asked questions

What causes bulging fontanelle (soft spot)?
Crying or straining (temporary, resolves when calm) (common); Vomiting or coughing (temporary) (common); Meningitis or encephalitis (uncommon); Hydrocephalus (fluid buildup in the brain) (uncommon); Intracranial hemorrhage (rare); Brain tumor (rare); Hypervitaminosis A (excess vitamin A) (rare)
When is this an emergency?
Fontanelle is bulging and baby has fever. Bulging fontanelle with seizures. Bulging fontanelle with inconsolable high-pitched crying. Bulging fontanelle with vomiting and lethargy. Bulging fontanelle after a head injury or fall. Baby is unresponsive or extremely difficult to wake with bulging fontanelle
What can I do at home?
Check fontanelle when baby is calm and in an upright position for accurate assessment. Know that brief bulging during crying, coughing, or straining is normal. Keep track of head circumference measurements at well-child visits. Note any changes in feeding patterns, alertness, or behavior. Do not press hard on the fontanelle — gentle touching will not harm the baby
When should I call the doctor?
Fontanelle seems slightly fuller than usual but baby is acting normally. Mildly tense fontanelle with no other symptoms

Sources

AAPMEDLINEPLUSNHS

All content follows our editorial policy and is reviewed against published clinical guidelines.

2,705 evidence-based guides6 authoritative medical sources

Related Symptoms

sunken fontanellefeverlethargy

Bottom line

Most cases of bulging fontanelle (soft spot) in babies are not emergencies. However, seek immediate care if fontanelle is bulging and baby has fever.

Trust your instincts. If something feels wrong, reach out to your pediatrician. Worrying about your baby means you care — that is a good thing.