Symptoms of Craniosynostosis

Craniosynostosis causes a baby's head to have a misshapen appearance. This is because the condition causes one or more of the flexible joints in a baby's skull, called sutures, to fuse together prematurely. The shape of the baby’s head depends on which suture fused too early.

Other possible symptoms include an asymmetrical face and a larger or smaller head than normal.

This article discusses the common and rare symptoms of craniosynostosis and its complications.

How Common Is Craniosynostosis?

Craniosynostosis affects one in every 2,500 live births. 

Baby boy at the doctor's office

FatCamera / Getty Images

Frequent Symptoms

The most frequent symptom of craniosynostosis is a misshapen head. The shape of your little one’s head depends on which type of craniosynostosis they have and which sutures fuse:

  • Sagittal synostosis appears as a long, narrow head. This head shape is known as scaphocephaly. The sagittal suture runs along the top of the head from front to back. This is the most common type of craniosynostosis.
  • Coronal synostosis presents as a flattened forehead. The coronal sutures run from the ear up to the top of the head on either side of the head. When one suture fuses, the forehead appears flattened on the affected side. This head shape is known as anterior plagiocephaly. You may notice that your baby’s eye socket appears higher on the affected side, and their nose may look like it's pulled up on that side as well. Coronal craniosynostosis is the second most common type of craniosynostosis.
  • Bicoronal synostosis appears as a broad, short head. This head shape is called brachycephaly. This condition occurs when both of the coronal sutures fuse and may be part of a larger genetic disorder.
  • Metopic synostosis causes a triangular-shaped head. This head shape is known as trigonocephaly. The metopic suture runs from the nose up to the top of the head. It causes your baby’s head to appear triangular, with the narrow part in the front and the broad part in the back. You may notice that your little one’s eyes appear close together. 
  • Lambdoid synostosis presents as a flattened back of the head. This head shape is called posterior plagiocephaly. The lambdoid suture runs along the back side of the head. This is a rare type of craniosynostosis that is often associated with a genetic disorder. 

Another Condition That Can Cause a Change in Your Baby's Head Shape

A change in your baby’s head shape does not always mean that the child has craniosynostosis. A much more common and benign (mild or harmless) condition can also cause these changes, and it's called positional plagiocephaly. Positional plagiocephaly describes a flattened part of the baby’s head due to often lying in the same position. This condition is most commonly seen in babies who often lie on their backs. 

Other typical symptoms of craniosynostosis include:

  • A disappearing fontanel: The fontanel, or soft spot, on top of your baby’s head usually remains open during their first year. When a suture near the fontanel fuses, the fontanel may close as well. 
  • A bulging fontanel: You may notice that your child’s fontanel appears full or bulging due to the increased pressure in the skull.
  • A hard ridge on the skull: When a suture in the skull fuses, a hard ridge usually forms. You and your doctor will likely be able to feel it by lightly pressing along the suture line. 
  • An asymmetrical face: Depending on which suture is fused, your child’s face may appear uneven or asymmetrical. You may notice that one eye is higher than the other or that part of their nose is pulling to one side. 

Rare Symptoms

Rarer symptoms of craniosynostosis include:

  • Prominent scalp veins: When you see your pediatrician, you may notice that the doctor will closely inspect your child’s head for prominent or bulging veins. This could indicate increased pressure inside the skull. 
  • Slowed head growth: Once the skull fuses, it is possible that your child’s head will stop growing like the rest of the baby's body. You may notice that their head circumference measurement falls off of the normal growth chart at their well-child visits with the pediatrician
  • Increased head size: While some children experience slowed head growth, others exhibit faster growth. This is likely due to increased pressure in the skull. 
  • Irritability: Some babies with craniosynostosis seem more irritable and have a high-pitched cry. 

Complications and Subgroup Indications

The most common complication of craniosynostosis is increased intracranial pressure. When the skull fuses prematurely and your little one’s brain continues to grow, the brain presses up against the skull. This causes increased pressure in the skull, which affects the brain and its development.

Symptoms of increased intracranial pressure in newborns and infants include:

  • Irritability
  • Vomiting
  • Sleepiness 
  • Keeping eyes down all of the time

When to See a Doctor or Go to the Hospital

It’s important to reach out to your pediatrician as soon as you notice any symptoms of craniosynostosis. Early diagnosis and treatment are vital to minimizing complications and increasing the likelihood of a successful treatment outcome.

A 2020 survey found that parents of babies with craniosynostosis often noticed that something was wrong before their medical team did. Parents voiced feelings of frustration that their doctor did not seem concerned about their child’s unusual head shape. If you feel like something is not right with your child, do not hesitate to continue asking questions of your medical team. 


The most common symptom of craniosynostosis is a misshapen head. The exact shape that your child's head takes depends on what type of craniosynostosis the child has and which sutures are affected.

You may also notice a disappearing or bulging soft spot, a hard ridge across the head, and an asymmetrical face. Talk to your child's pediatrician as soon as you notice these symptoms. Early diagnosis and treatment can ensure that this condition does not interfere with your child's development.

A Word From Verywell

The most common symptom of craniosynostosis is a misshapen head. This common birth defect affects about one in every 2,500 live births. Supporting your child during the diagnosis and treatment period is overwhelming for any parent. It may be helpful to remember that craniosynostosis is usually treatable with surgery.

Stay in close contact with your medical team and consider reaching out to a support group or online community.

Frequently Asked Questions

Who is at risk of craniosynostosis?

Craniosynostosis is a relatively common birth defect with one case in every 2,500 live births. Most cases are considered random and do not have a known cause. Possible risk factors for having a baby with craniosynostosis include maternal thyroid disease and the use of fertility medication. Talk with your obstetrician if you are concerned.

How is craniosynostosis diagnosed?

Craniosynostosis is often diagnosed by physical exam. Your doctor will conduct a thorough exam and ask questions about your child’s health. Your child may also need a computed tomography scan (CT scan) to confirm the diagnosis. A CT with 3D reconstruction is the most accurate test for diagnosing craniosynostosis.

When can craniosynostosis be detected?

Depending on how severe the skull malformation is, craniosynostosis can be diagnosed anytime during your child’s first year of life. Some children are diagnosed at birth, while others are diagnosed during a well-child exam a few months later. 

Is the surgery for craniosynostosis brain surgery?

No, the surgery for craniosynostosis involves moving the skull bones into a more circular shape, with the goal of providing room for the brain to grow. The surgeon will not perform surgery directly on the brain. 

7 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  5. MedlinePlus. Increased intracranial pressure.

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By Carrie Madormo, RN, MPH
Carrie Madormo, RN, MPH, is a health writer with over a decade of experience working as a registered nurse. She has practiced in a variety of settings including pediatrics, oncology, chronic pain, and public health.