My Baby's Soft Spot Looks Sunken
Medically reviewed by Dr. Michael Okonkwo, MD, FAAP · Board-Certified Neonatologist
Content reviewed against published AAP, CDC, AAP guidelines
Last reviewed:
If your baby has been diagnosed with or you suspect soft spot looks sunken, here is what the evidence says.
The short answer
A sunken fontanelle (soft spot) is most often a sign of dehydration and needs prompt attention. In a well-hydrated baby, the fontanelle should feel flat and firm, though it may dip slightly when your baby is upright or crying. If it appears noticeably sunken, especially with other signs like fewer wet diapers or dry lips, contact your pediatrician.
Key takeaways
- A sunken fontanelle (soft spot) is most often a sign of dehydration and needs prompt attention. In a well-hydrated baby, the fontanelle should feel flat and firm, though it may dip slightly when your baby is upright or crying. If it appears noticeably sunken, especially with other signs like fewer wet diapers or dry lips, contact your pediatrician.
- Usually normal when: Your baby's fontanelle appears very slightly lower when they're upright versus lying down
- Call your doctor if: Your baby has a clearly sunken fontanelle along with fewer wet diapers, no tears when crying, dry lips, or lethargy
- Varies by age — see the age-by-age breakdown below
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What Parents Should Know
According to AAP, CDC guidelines, a sunken fontanelle (soft spot) is most often a sign of dehydration and needs prompt attention. In a well-hydrated baby, the fontanelle should feel flat and firm, though it may dip slightly when your baby is upright or crying. If it appears noticeably sunken, especially with other signs like fewer wet diapers or dry lips, contact your pediatrician. At 0-3 months, newborns can become dehydrated quickly due to their small size. A sunken fontanelle in a young baby, especially if accompanied by poor feeding, fewer than 6 wet diapers per day, or lethargy, needs same-day medical evaluation. Feeding difficulties or illness can lead to dehydration rapidly at this age. It is generally considered normal when your baby's fontanelle appears very slightly lower when they're upright versus lying down. However, you should contact your pediatrician promptly if your baby has a clearly sunken fontanelle along with fewer wet diapers, no tears when crying, dry lips, or lethargy.
Normal vs. Concerning
When to Seek Immediate Care
- Your baby has a clearly sunken fontanelle along with fewer wet diapers, no tears when crying, dry lips, or lethargy
- Your baby has persistent vomiting or diarrhea and is unable to keep fluids down
- Your baby is listless, difficult to wake, or seems very unwell
- Your newborn (under 3 months) has a sunken fontanelle and is feeding poorly
By Age
What to expect by age
0-3 months
Newborns can become dehydrated quickly due to their small size. A sunken fontanelle in a young baby, especially if accompanied by poor feeding, fewer than 6 wet diapers per day, or lethargy, needs same-day medical evaluation. Feeding difficulties or illness can lead to dehydration rapidly at this age.
3-6 months
At this age, you may notice slight variations in how the fontanelle looks depending on whether your baby is lying down, sitting, or crying. A very slight dip when upright is normal. However, a clearly sunken fontanelle, especially in a baby who seems unwell, has diarrhea, or is vomiting, is a red flag for dehydration.
6-12 months
As your baby grows, the anterior fontanelle begins to close (this process is complete by 18-24 months). A sunken soft spot at this age, combined with reduced fluid intake, diarrhea, or vomiting, should prompt a call to your pediatrician. Your baby may need extra fluids or medical assessment.
12-18 months
The fontanelle is smaller now and harder to assess, but it should still not appear sunken. Stomach bugs, heat, or refusing fluids during illness can all lead to dehydration. Trust your instinct - if your toddler seems unwell and the soft spot looks noticeably dipped, seek medical advice.
18 months+
Most children's fontanelles close between 18 and 24 months. Once closed, you can no longer use the soft spot as an indicator of hydration. If your toddler is dehydrated, look for other signs: dry mouth, no tears when crying, fewer wet diapers, and lethargy.
What to Tell Your Pediatrician
- Describe when you first noticed soft spot looks sunken and how it has changed over time.
- Note your baby's current age and which age-specific patterns you are seeing.
- Mention if you're unsure whether the fontanelle looks sunken or normal.
- Mention if your baby has had a mild stomach bug and you want to confirm they're well-hydrated.
- Bring a list of any questions or observations you want to discuss at the appointment.
What Should You Do?
When to take action
- Your baby's fontanelle appears very slightly lower when they're upright versus lying down
- The soft spot dips briefly when your baby cries or strains during a bowel movement
- Your baby is feeding well, has plenty of wet diapers (6+ per day for infants), and seems happy
- The fontanelle feels soft and flat when your baby is calm and lying down
- You're unsure whether the fontanelle looks sunken or normal
- Your baby has had a mild stomach bug and you want to confirm they're well-hydrated
- The fontanelle seems to look different than it used to, but your baby is otherwise well
- Your baby has a clearly sunken fontanelle along with fewer wet diapers, no tears when crying, dry lips, or lethargy
- Your baby has persistent vomiting or diarrhea and is unable to keep fluids down
- Your baby is listless, difficult to wake, or seems very unwell
- Your newborn (under 3 months) has a sunken fontanelle and is feeding poorly
What You Can Do at Home
- Keep track of when you notice soft spot looks sunken — noting the time of day, duration, and any triggers can help your pediatrician.
- Remember that your baby's fontanelle appears very slightly lower when they're upright versus lying down — this is generally within the range of normal.
- At 0-3 months, focus on observation rather than intervention unless your pediatrician advises otherwise.
- Follow any care instructions from your pediatrician. Keep a written log of symptoms to bring to appointments.
- While monitoring at home, seek immediate care if your baby has a clearly sunken fontanelle along with fewer wet diapers, no tears when crying, dry lips, or lethargy.
Related Resources
Frequently asked questions
Is soft spot looks sunken normal?
When should I call the doctor about soft spot looks sunken?
When is soft spot looks sunken normal?
What causes soft spot looks sunken?
What should I mention to my pediatrician about soft spot looks sunken?
Is soft spot looks sunken normal at 0-3 months?
Is soft spot looks sunken normal at 3-6 months?
Should I go to the ER for soft spot looks sunken?
Does soft spot looks sunken go away on its own?
References
- [1]American Academy of Pediatrics. Baby Soft Spots (Fontanelles). HealthyChildren.org, 2024. AAP
- [2]Centers for Disease Control and Prevention. Diarrhea: Common Illness, Global Killer. CDC Global Health, 2015. CDC
- [3]American Academy of Pediatrics. Dehydration in Children. HealthyChildren.org, 2024. AAP
Doctor Visit Checklist
Bring this checklist to your next pediatrician visit to discuss My Baby's Soft Spot Looks Sunken.
Things to mention
- Describe when you first noticed soft spot looks sunken and how it has changed over time.
- Note your baby's current age and which age-specific patterns you are seeing.
- Mention if you're unsure whether the fontanelle looks sunken or normal.
- Mention if your baby has had a mild stomach bug and you want to confirm they're well-hydrated.
- Bring a list of any questions or observations you want to discuss at the appointment.
Observations to share
- You're unsure whether the fontanelle looks sunken or normal
- Your baby has had a mild stomach bug and you want to confirm they're well-hydrated
- The fontanelle seems to look different than it used to, but your baby is otherwise well
Urgent signs to report immediately
- Your baby has a clearly sunken fontanelle along with fewer wet diapers, no tears when crying, dry lips, or lethargy
- Your baby has persistent vomiting or diarrhea and is unable to keep fluids down
- Your baby is listless, difficult to wake, or seems very unwell
My notes
From ismybabyalright.com — free, evidence-based baby health guides
All content follows our editorial policy and is reviewed against published clinical guidelines.
2,705 evidence-based guides6 authoritative medical sources5 medical advisory board members
Related Resources
Bottom line
Most cases of soft spot looks sunken are normal. Talk to your pediatrician if your baby has a clearly sunken fontanelle along with fewer wet diapers, no tears when crying, dry lips, or lethargy.
Trust your instincts. If something feels wrong, reach out to your pediatrician. Worrying about your baby means you care — that is a good thing.
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